Solving simple linear equations. Solving real examples of simple linear equations

52. More complex examples equations.
Example 1.

5/(x – 1) – 3/(x + 1) = 15/(x 2 – 1)

The common denominator is x 2 – 1, since x 2 – 1 = (x + 1)(x – 1). Let's multiply both sides of this equation by x 2 – 1. We get:

or, after reduction,

5(x + 1) – 3(x – 1) = 15

5x + 5 – 3x + 3 = 15

2x = 7 and x = 3½

Let's consider another equation:

5/(x-1) – 3/(x+1) = 4(x 2 – 1)

Solving as above, we get:

5(x + 1) – 3(x – 1) = 4
5x + 5 – 3x – 3 = 4 or 2x = 2 and x = 1.

Let's see whether our equalities are justified if we replace x in each of the considered equations with the found number.

For the first example we get:

We see that there is no room for any doubts: we have found a number for x such that the required equality is justified.

For the second example we get:

5/(1-1) – 3/2 = 15/(1-1) or 5/0 – 3/2 = 15/0

Here doubts arise: we are faced with division by zero, which is impossible. If in the future we manage to give a certain, albeit indirect, meaning to this division, then we can agree that the found solution x – 1 satisfies our equation. Until then, we must admit that our equation does not have a solution that has a direct meaning.

Such cases can occur when the unknown is somehow included in the denominators of the fractions present in the equation, and some of these denominators, when the solution is found, turn to zero.

Example 2.

You can immediately see that this equation has the form of a proportion: the ratio of the number x + 3 to the number x – 1 is equal to the ratio of the number 2x + 3 to the number 2x – 2. Let someone, in view of this circumstance, decide to apply here to free the equation from fractions, the main property of proportion (the product of the extreme terms is equal to the product of the middle terms). Then he will get:

(x + 3) (2x – 2) = (2x + 3) (x – 1)

2x 2 + 6x – 2x – 6 = 2x 2 + 3x – 2x – 3.

Here, fears that we will not cope with this equation may be raised by the fact that the equation includes terms with x 2. However, we can subtract 2x 2 from both sides of the equation - this will not break the equation; then the terms with x 2 are destroyed and we get:

6x – 2x – 6 = 3x – 2x – 3

Let's move the unknown terms to the left and the known ones to the right - we get:

3x = 3 or x = 1

Remembering this equation

(x + 3)/(x – 1) = (2x + 3)/(2x – 2)

We will immediately notice that the found value for x (x = 1) makes the denominators of each fraction vanish; We must abandon such a solution until we have considered the question of division by zero.

If we also note that the application of the property of proportion has complicated the matter and that a simpler equation could be obtained by multiplying both sides of the given by a common denominator, namely 2(x – 1) - after all, 2x – 2 = 2 (x – 1) , then we get:

2(x + 3) = 2x – 3 or 2x + 6 = 2x – 3 or 6 = –3,

which is impossible.

This circumstance indicates that this equation does not have any solutions that have a direct meaning that would not turn the denominators of this equation to zero.
Let us now solve the equation:

(3x + 5)/(x – 1) = (2x + 18)/(2x – 2)

Let's multiply both sides of the equation 2(x – 1), i.e. by a common denominator, we get:

6x + 10 = 2x + 18

The found solution does not make the denominator vanish and has a direct meaning:

or 11 = 11

If someone, instead of multiplying both parts by 2(x – 1), were to use the property of proportion, they would get:

(3x + 5)(2x – 2) = (2x + 18)(x – 1) or
6x 2 + 4x – 10 = 2x 2 + 16x – 18.

Here the terms with x 2 would not be destroyed. Moving all the unknown terms to the left side, and the known ones to the right, we would get

4x 2 – 12x = –8

x 2 – 3x = –2

Now we will not be able to solve this equation. In the future, we will learn how to solve such equations and find two solutions for it: 1) you can take x = 2 and 2) you can take x = 1. It’s easy to check both solutions:

1) 2 2 – 3 2 = –2 and 2) 1 2 – 3 1 = –2

If we remember the initial equation

(3x + 5) / (x – 1) = (2x + 18) / (2x – 2),

then we will see that now we get both of its solutions: 1) x = 2 is the solution that has a direct meaning and does not turn the denominator to zero, 2) x = 1 is the solution that turns the denominator to zero and does not have a direct meaning .

Example 3.

Let’s find the common denominator of the fractions included in this equation by factoring each of the denominators:

1) x 2 – 5x + 6 = x 2 – 3x – 2x + 6 = x(x – 3) – 2(x – 3) = (x – 3)(x – 2),

2) x 2 – x – 2 = x 2 – 2x + x – 2 = x (x – 2) + (x – 2) = (x – 2)(x + 1),

3) x 2 – 2x – 3 = x 2 – 3x + x – 3 = x (x – 3) + (x – 3) = (x – 3) (x + 1).

The common denominator is (x – 3)(x – 2)(x + 1).

Let's multiply both sides of this equation (and we can now rewrite it as:

by a common denominator (x – 3) (x – 2) (x + 1). Then, after reducing each fraction we get:

3(x + 1) – 2(x – 3) = 2(x – 2) or
3x + 3 – 2x + 6 = 2x – 4.

From here we get:

–x = –13 and x = 13.

This solution has a direct meaning: it does not make any of the denominators vanish.

If we took the equation:

then, doing exactly the same as above, we would get

3(x + 1) – 2(x – 3) = x – 2

3x + 3 – 2x + 6 = x – 2

3x – 2x – x = –3 – 6 – 2,

where would you get it from?

which is impossible. This circumstance shows that it is impossible to find a solution for the last equation that has a direct meaning.

How to learn to solve simple and complex equations

Dear parents!

Without basic mathematical training, education is impossible modern man. At school, mathematics serves as a supporting subject for many related disciplines. In post-school life, it becomes a real necessity continuing education, which requires basic general school training, including mathematics.

IN primary school not only knowledge on the main topics is laid, but also develops logical thinking, imagination and spatial representations, as well as the formation of interest in this subject.

Observing the principle of continuity, we will focus on the most important topic, namely, “The relationship between the components of actions in solving compound equations.”

By using this lesson you can easily learn to solve complex equations. In this lesson you will learn in detail about step by step instructions solving complicated equations.

Many parents are perplexed by the question of how to get their children to learn to solve simple and complex equations. If the equations are simple, that’s half the problem, but there are also complex ones - for example, integral ones. By the way, for information, there are also equations that people are struggling to solve the best minds our planet and for the solution of which very significant cash prizes are given. For example, if you rememberPerelmanand an unclaimed cash bonus of several million.

However, let us first return to simple mathematical equations and repeat the types of equations and the names of the components. A little warm-up:

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WARM-UP

Find the extra number in each column:

2) What word is missing in each column?

3) Connect the words from the first column with the words from the 2nd column.

"Equation" "Equality"

4) How do you explain what “equality” is?

5) What about the “equation”? Is this equality? What's special about it?

sum term

minuend difference

subtractive product

factorequality

dividend

the equation

Conclusion: An equation is an equality with a variable whose value must be found.

_______________________________________________________________________

I invite each group to write equations on a piece of paper with a felt-tip pen: (on the board)

Group 1 - with an unknown term;

group 2 - with an unknown decrement;

Group 3 - with an unknown subtrahend;

group 4 - with an unknown divisor;

group 5 - with an unknown dividend;

Group 6 - with an unknown multiplier.

1 group x + 8 = 15

Group 2 x - 8 = 7

3 group 48 - x = 36

4 group 540: x = 9

5 group x: 15 = 9

6 group x * 10 = 360

One of the group must read their equation in mathematical language and comment on their solution, i.e., speak out the operation being performed with the known components of the actions (algorithm).

Conclusion: We can solve simple equations of all types using an algorithm, read and write literal expressions.

I propose to solve a problem in which a new type of equation appears.

Conclusion: We got acquainted with the solution of equations, one of the parts of which contains a numerical expression, the value of which must be found and a simple equation must be obtained.

________________________________________________________________________

Let's consider another version of the equation, the solution of which is reduced to solving a chain of simple equations. Here's one introduction to compound equations.

a + b * c (x - y) : 3 2 * d + (m - n)

Are equations written?

Why?

What are such actions called?

Read them by calling last action:

No. These are not equations because the equation must have an “=” sign.

Expressions

a + b * c - the sum of the number a and the product of the numbers b and c;

(x - y): 3 - quotient of the difference between the numbers x and y;

2 * d + (m - n) - the sum of double the number d and the difference between the numbers m and n.

I suggest everyone write down a sentence in mathematical language:

The product of the difference between the numbers x and 4 and the number 3 is 15.

CONCLUSION: The emerging problematic situation motivates the setting of the lesson goal: to learn to solve equations in which the unknown component is an expression. Such equations are compound equations.

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Or maybe the types of equations we have already studied will help us? (algorithms)

Which of the famous equations is our equation similar to? X * a = b

VERY IMPORTANT QUESTION: What is the expression on the left side - sum, difference, product or quotient?

(x - 4) * 3 = 15 (Product)

Why? (since the last action is multiplication)

Conclusion:Such equations have not yet been considered. But we can solve it if the expressionx - 4put a card (y - igrek), and you get an equation that can be easily solved using a simple algorithm for finding the unknown component.

When solving compound equations, it is necessary at each step to select an action at an automated level, commenting and naming the components of the action.

Simplify part

No

Yes

(y - 5) * 4 = 28
y - 5 = 28: 4
y - 5 = 7
y = 5 +7
y = 12
(12 - 5) * 4 = 28
28 = 28 (i)

Conclusion:In classes with different backgrounds, this work can be organized differently. In more prepared classes, even for primary consolidation, expressions can be used in which not two, but three or more actions, but their solution requires more steps, each step simplifying the equation until you get a simple equation. And each time you can observe how the unknown component of actions changes.

_____________________________________________________________________________

CONCLUSION:

When we are talking about something very simple and understandable, we often say: “The matter is as clear as two and two are four!”

But before they figured out that two and two equal four, people had to study for many, many thousands of years.

Many rules from school textbooks on arithmetic and geometry were known to the ancient Greeks more than two thousand years ago.

Wherever you need to count, measure, compare something, you cannot do without mathematics.

It is difficult to imagine how people would live if they did not know how to count, measure, and compare. Mathematics teaches this.

Today you plunged into school life, played the role of students, and I invite you, dear parents, to rate your skills on a scale.

My skills

Date and rating

Action components.

Drawing up an equation with an unknown component.

Reading and writing expressions.

Find the root of a simple equation.

Find the root of an equation where one of the parts contains a numerical expression.

Find the root of an equation in which the unknown component of the action is an expression.

There are moments in life when a seemingly hopeless situation appears in front of you, or a problem, any resolution of which promises to be not in your favor. Don’t rush to give up on realizing your dreams, achieving your goals, or panic. One ancient sage said: “Choose time to think - this is a source of strength.” Well, it’s hard to disagree with him, because the mind is powerful weapon. Even the most complex problem has dozens of solutions, and it is out of sight only because people are accustomed to thinking within certain frameworks. To solve a complex problem, you need to coordinate the work of the conscious and subconscious - this will broaden your horizons and allow you to see new possibilities.

“100 ideas” technique

To master the “100 Ideas” technique, you will only need 1-2 hours of free time, a comfortable personal corner where no one will disturb you, as well as paper and pencil. Ask your loved ones and acquaintances in advance not to distract you during “meditation”, turn off your phone and just relax. At the top of a piece of paper, formulate and write down your question or dilemma. Number the list from one to 100 and start generating ideas.

At first, ideas come one after another, although they, alas, are not new - you will describe all your “trump cards”, including skills, acquaintances, connections, financial resources, time that you can devote to solving the problem. Then it will still seem impossible to find a hundred answers, and if you stumble on the 20-30th point, you will feel empty. A slight hitch awaits you, which naturally occurs when the consciousness, walking in a vicious circle, has exhausted the options available to it and has gone through everything that it has already encountered in personal experience.


The second phase of your journey to your subconscious is another 40 points where you are still using your conscious mind, but your hidden forces they begin to wake up and get a second wind. At this stage, your way of thinking emerges. You will notice that your ideas begin to repeat themselves and contain all sorts of clichés and attitudes. Your goal is not to brush them aside, but to carefully write them down on paper, and here’s why: these stamps are the frames beyond which you cannot go and look around. It could be public opinion, dissatisfaction with your superiors, lack of self-confidence and any other “burrs” in your psyche. At the same time, you can discover your hidden problems or fears that prevent you from moving forward. This stage will require the greatest endurance from you - after all, it is not at all easy to brush aside the first thirty points, which are clearly in your comfort zone, and take on new, unknown and therefore sometimes frightening ideas - this is normal, the main thing is not to give up. Moreover, this internal struggle only helps to move on to the third phase of the journey.

It is the last 30 points that will open Pandora’s box in front of you, because the number 100 was not chosen by chance. It is this that allows your intuition to fully open up and surprise yourself with unexpected “insights from above” - impromptu expressions of your awakening subconscious, from where ideas appear without any processing or filtering by the mind. In your search, you have already abandoned logic, noticing how square it really is, and you understand that your way of thinking lay only in one plane - and the world, it turns out, is three-dimensional (not counting time). Now, when the mind stops dictating to you what is “possible” and what is “not allowed,” the door to the subconscious swings open. You can easily invent something out of the ordinary and, at first glance, completely absurd. It may even seem to you that you shouldn’t write down an idea that is clearly unsuitable for you, an idea that suddenly appeared in your head. However, it is strange, sometimes stupid phrases that can turn out to be diamonds in the rough. Remember how people considered the Earth to be flat and were afraid to fall off its edge, and how the idea that the planet was round and rotated was once called heresy. Delusional ideas may not be clear to you at first, but you will feel that there is something in them - this will serve as a straw that will point you in the right direction.


It may also happen that after putting out so many ideas, you suddenly realize that this was not a problem at all - or you only saw the tip of the iceberg, so you need to make a new list to answer a completely different question.

There are a few more rules that must be followed when working with this technique. First of all, the list must be compiled in one go, without interruptions - otherwise your dormant brilliant ideas will remain dormant under the weight of everyday thinking. While working, you should not re-read the list and evaluate how much has already been done and how many items remain - this will distract you and prevent your thoughts from naturally repeating themselves - and therefore will not allow you to see your own stumbling blocks. Get ready right away: you will evaluate and criticize your ideas after compiling all the hundred points - and while the process is going on, you need to write down any thoughts (you don’t have to show this paper to anyone if you don’t want to). If the work is in full swing, shorten the words, the main thing is that you can then read what you meant. You can, of course, use a laptop instead of pencil and paper, but remember: source electromagnetic waves, at least in theory, prevents your brain, aura and, if you will, chakras from connecting to the universal mind - and generally functioning healthily. But this is at personal discretion.

“Delicious” bonuses of the “100 Ideas” technique are not only in the possibility of deep self-analysis and finding original solutions to difficult situations, but also in the fact that with it you can develop diversified and plan your future, find new incentives for self-development and grow above yourself . To do this, at your leisure, reflect on the answers to the topics below (or any of your own):

  • How to educate yourself
  • How to improve relationships
  • How to improve your life
  • How to make money
  • How to improve your business
  • How to help people
  • How to increase personal effectiveness
  • How to become healthier
  • Things I keep putting off until tomorrow
  • The things I do best
  • Things that demotivate me
  • Qualities I want to develop in myself
  • Questions I need answers to
  • Values ​​I Believe in
  • Things I value in life
  • Professions I want to try myself in
  • Things (people) that slow me down in achieving my goal
  • Things that cheer me up
  • Conclusions that life has taught me
  • Things you can get rid of
  • Places I would like to visit
  • Mistakes for which I forgive myself (others)
  • Ways to think more creatively


In this video we will analyze the whole set linear equations, which are solved using the same algorithm - that’s why they are called the simplest.

First, let's define: what is a linear equation and which one is called the simplest?

A linear equation is one in which there is only one variable, and only to the first degree.

The simplest equation means the construction:

All other linear equations are reduced to the simplest using the algorithm:

  1. Expand parentheses, if any;
  2. Move terms containing a variable to one side of the equal sign, and terms without a variable to the other;
  3. Give similar terms to the left and right of the equal sign;
  4. Divide the resulting equation by the coefficient of the variable $x$.

Of course, this algorithm does not always help. The fact is that sometimes after all these machinations the coefficient of the variable $x$ turns out to be equal to zero. In this case, two options are possible:

  1. The equation has no solutions at all. For example, when something like $0\cdot x=8$ turns out, i.e. on the left is zero, and on the right is a number other than zero. In the video below we will look at several reasons why this situation is possible.
  2. The solution is all numbers. The only case, when this is possible, the equation is reduced to the construction $0\cdot x=0$. It is quite logical that no matter what $x$ we substitute, it will still turn out “zero is equal to zero”, i.e. correct numerical equality.

Now let's see how all this works using real-life examples.

Examples of solving equations

Today we are dealing with linear equations, and only the simplest ones. In general, a linear equation means any equality that contains exactly one variable, and it goes only to the first degree.

Such constructions are solved in approximately the same way:

  1. First of all, you need to expand the parentheses, if there are any (as in our last example);
  2. Then combine similar
  3. Finally, isolate the variable, i.e. move everything connected with the variable—the terms in which it is contained—to one side, and move everything that remains without it to the other side.

Then, as a rule, you need to bring similar ones on each side of the resulting equality, and after that all that remains is to divide by the coefficient of “x”, and we will get the final answer.

In theory, this looks nice and simple, but in practice, even experienced high school students can make offensive mistakes in fairly simple linear equations. Typically, errors are made either when opening brackets or when calculating the “pluses” and “minuses”.

In addition, it happens that a linear equation has no solutions at all, or that the solution is the entire number line, i.e. any number. We will look at these subtleties in today's lesson. But we will start, as you already understood, with the very simple tasks.

Scheme for solving simple linear equations

First, let me once again write the entire scheme for solving the simplest linear equations:

  1. Expand the brackets, if any.
  2. We isolate the variables, i.e. We move everything that contains “X’s” to one side, and everything without “X’s” to the other.
  3. We present similar terms.
  4. We divide everything by the coefficient of “x”.

Of course, this scheme does not always work; there are certain subtleties and tricks in it, and now we will get to know them.

Solving real examples of simple linear equations

Task No. 1

The first step requires us to open the brackets. But they are not in this example, so we skip this step. In the second step we need to isolate the variables. Please note: we are talking only about individual terms. Let's write it down:

We present similar terms on the left and right, but this has already been done here. Therefore, we move on to the fourth step: divide by the coefficient:

\[\frac(6x)(6)=-\frac(72)(6)\]

So we got the answer.

Task No. 2

We can see the parentheses in this problem, so let's expand them:

Both on the left and on the right we see approximately the same design, but let's act according to the algorithm, i.e. separating the variables:

Here are some similar ones:

At what roots does this work? Answer: for any. Therefore, we can write that $x$ is any number.

Task No. 3

The third linear equation is more interesting:

\[\left(6-x \right)+\left(12+x \right)-\left(3-2x \right)=15\]

There are several brackets here, but they are not multiplied by anything, they are simply preceded by different signs. Let's break them down:

We perform the second step already known to us:

\[-x+x+2x=15-6-12+3\]

Let's do the math:

We carry out the last step - divide everything by the coefficient of “x”:

\[\frac(2x)(x)=\frac(0)(2)\]

Things to Remember When Solving Linear Equations

If we ignore too simple tasks, I would like to say the following:

  • As I said above, not every linear equation has a solution - sometimes there are simply no roots;
  • Even if there are roots, there may be zero among them - there is nothing wrong with that.

Zero is the same number as the others; you shouldn’t discriminate against it in any way or assume that if you get zero, then you did something wrong.

Another feature is related to the opening of brackets. Please note: when there is a “minus” in front of them, we remove it, but in parentheses we change the signs to opposite. And then we can open it using standard algorithms: we will get what we saw in the calculations above.

Understanding this simple fact will allow you to avoid making stupid and offensive mistakes in high school, when doing such actions is taken for granted.

Solving complex linear equations

Let's move on to more complex equations. Now the constructions will become more complex and when performing various transformations a quadratic function will appear. However, we should not be afraid of this, because if, according to the author’s plan, we are solving a linear equation, then during the transformation process all monomials containing a quadratic function will certainly cancel.

Example No. 1

Obviously, the first step is to open the brackets. Let's do this very carefully:

Now let's take a look at privacy:

\[-x+6((x)^(2))-6((x)^(2))+x=-12\]

Here are some similar ones:

Obviously, this equation has no solutions, so we’ll write this in the answer:

\[\varnothing\]

or there are no roots.

Example No. 2

We perform the same actions. First step:

Let's move everything with a variable to the left, and without it - to the right:

Here are some similar ones:

Obviously, this linear equation has no solution, so we’ll write it this way:

\[\varnothing\],

or there are no roots.

Nuances of the solution

Both equations are completely solved. Using these two expressions as an example, we were once again convinced that even in the simplest linear equations, everything may not be so simple: there can be either one, or none, or infinitely many roots. In our case, we considered two equations, both simply have no roots.

But I would like to draw your attention to another fact: how to work with parentheses and how to open them if there is a minus sign in front of them. Consider this expression:

Before opening, you need to multiply everything by “X”. Please note: multiplies each individual term. Inside there are two terms - respectively, two terms and multiplied.

And only after these seemingly elementary, but very important and dangerous transformations have been completed, can you open the bracket from the point of view of the fact that there is a minus sign after it. Yes, yes: only now, when the transformations are completed, we remember that there is a minus sign in front of the brackets, which means that everything below simply changes signs. At the same time, the brackets themselves disappear and, most importantly, the front “minus” also disappears.

We do the same with the second equation:

It is not by chance that I pay attention to these small, seemingly insignificant facts. Because solving equations is always a sequence of elementary transformations, where the inability to clearly and competently perform simple actions leads to the fact that high school students come to me and again learn to solve such simple equations.

Of course, the day will come when you will hone these skills to the point of automaticity. You will no longer have to perform so many transformations each time; you will write everything on one line. But while you are just learning, you need to write each action separately.

Solving even more complex linear equations

What we are going to solve now can hardly be called the simplest task, but the meaning remains the same.

Task No. 1

\[\left(7x+1 \right)\left(3x-1 \right)-21((x)^(2))=3\]

Let's multiply all the elements in the first part:

Let's do some privacy:

Here are some similar ones:

Let's complete the last step:

\[\frac(-4x)(4)=\frac(4)(-4)\]

Here is our final answer. And, despite the fact that in the process of solving we had coefficients with a quadratic function, they canceled each other out, which makes the equation linear and not quadratic.

Task No. 2

\[\left(1-4x \right)\left(1-3x \right)=6x\left(2x-1 \right)\]

Let's carefully perform the first step: multiply each element from the first bracket by each element from the second. There should be a total of four new terms after the transformations:

Now let’s carefully perform the multiplication in each term:

Let’s move the terms with “X” to the left, and those without - to the right:

\[-3x-4x+12((x)^(2))-12((x)^(2))+6x=-1\]

Here are similar terms:

Once again we have received the final answer.

Nuances of the solution

The most important note about these two equations is the following: as soon as we begin to multiply brackets that contain more than one term, this is done according to the following rule: we take the first term from the first and multiply with each element from the second; then we take the second element from the first and similarly multiply with each element from the second. As a result, we will have four terms.

About the algebraic sum

With this last example, I would like to remind students what an algebraic sum is. In classical mathematics, by $1-7$ we mean a simple construction: subtract seven from one. In algebra, we mean the following by this: to the number “one” we add another number, namely “minus seven”. This is how an algebraic sum differs from an ordinary arithmetic sum.

As soon as, when performing all the transformations, each addition and multiplication, you begin to see constructions similar to those described above, you simply will not have any problems in algebra when working with polynomials and equations.

Finally, let's look at a couple more examples that will be even more complex than the ones we just looked at, and to solve them we will have to slightly expand our standard algorithm.

Solving equations with fractions

To solve such tasks, we will have to add one more step to our algorithm. But first, let me remind you of our algorithm:

  1. Open the brackets.
  2. Separate variables.
  3. Bring similar ones.
  4. Divide by the ratio.

Alas, this wonderful algorithm, for all its effectiveness, turns out to be not entirely appropriate when we have fractions in front of us. And in what we will see below, we have a fraction on both the left and the right in both equations.

How to work in this case? Yes, it's very simple! To do this, you need to add one more step to the algorithm, which can be done both before and after the first action, namely, getting rid of fractions. So the algorithm will be as follows:

  1. Get rid of fractions.
  2. Open the brackets.
  3. Separate variables.
  4. Bring similar ones.
  5. Divide by the ratio.

What does it mean to “get rid of fractions”? And why can this be done both after and before the first standard step? In fact, in our case, all fractions are numerical in their denominator, i.e. Everywhere the denominator is just a number. Therefore, if we multiply both sides of the equation by this number, we will get rid of fractions.

Example No. 1

\[\frac(\left(2x+1 \right)\left(2x-3 \right))(4)=((x)^(2))-1\]

Let's get rid of the fractions in this equation:

\[\frac(\left(2x+1 \right)\left(2x-3 \right)\cdot 4)(4)=\left(((x)^(2))-1 \right)\cdot 4\]

Please note: everything is multiplied by “four” once, i.e. just because you have two parentheses doesn't mean you have to multiply each one by "four." Let's write down:

\[\left(2x+1 \right)\left(2x-3 \right)=\left(((x)^(2))-1 \right)\cdot 4\]

Now let's expand:

We seclude the variable:

We perform the reduction of similar terms:

\[-4x=-1\left| :\left(-4 \right) \right.\]

\[\frac(-4x)(-4)=\frac(-1)(-4)\]

We have received the final solution, let's move on to the second equation.

Example No. 2

\[\frac(\left(1-x \right)\left(1+5x \right))(5)+((x)^(2))=1\]

Here we perform all the same actions:

\[\frac(\left(1-x \right)\left(1+5x \right)\cdot 5)(5)+((x)^(2))\cdot 5=5\]

\[\frac(4x)(4)=\frac(4)(4)\]

The problem is solved.

That, in fact, is all I wanted to tell you today.

Key points

Key findings are:

  • Know the algorithm for solving linear equations.
  • Ability to open brackets.
  • Don't worry if you see quadratic functions, most likely, in the process of further transformations they will decrease.
  • There are three types of roots in linear equations, even the simplest ones: one single root, the entire number line is a root, and no roots at all.

I hope this lesson will help you master a simple, but very important topic for further understanding of all mathematics. If something is not clear, go to the site and solve the examples presented there. Stay tuned, many more interesting things await you!

Scientists have studied the rhythms of brain activity and identified the one that is best suited for creative insight and search. useful ideas

Scientists have studied the rhythms of brain activity and identified the one that is best suited for creative insight and the search for useful ideas.

Eat. Sleep. Solve problems. Repeat. Most likely, not counting a night's sleep, you spend most of your time to solve various problems - especially at work.

Not that it's a bad thing. Many of best entrepreneurs from Sarah Blakely to Richard Branson, owe their success to their ability to identify problems (in this case, unmet consumer needs) and provide solutions.

But whichever important part our lives have not been about problem solving, it is stress after all, and some people seem to cope with it better than others.

Therefore, for those who want to become more successful in this game, you can try something new: look for solutions in a dream. Literally. It is called “catch your theta rhythm”. No, we're not talking about self-hypnosis or meditation: it's pure science and it works.

But let's figure it out first:

What are brain rhythms?

As teacher Ned Herrmann explains, this rhythms governing the electrical activity of the brain. Depending on your activity level Four different rhythms can be distinguished. We list them in order of decreasing wave frequency.

  • During periods of maximum activity (for example, during an important interview), your brain works in beta rhythm.
  • When you are relaxed, such as when you have just finished big project and you can finally exhale, - the brain switches to alpha rhythm.
  • Now let's jump ahead: the fourth rhythm is indicated by the letter "delta" and is recorded when you are in deep sleep.

We skipped the third stage, theta rhythm, because it is the one that is best suited for solving problems. Herrmann says:

“People who spend a lot of time driving often come up with good ideas during these periods when they are in the theta rhythm... This can happen in the shower or bath, and even while shaving or combing their hair. This is a state in which solving a problem becomes so automatic that you can mentally abstract yourself from it. With the theta rhythm, it often seems that the flow of thoughts is not limited by anything - neither by internal censorship, nor by feelings of guilt.”

The brain enters this state, including when falling asleep or waking up, when you are balancing between wakefulness and deep sleep. Herrmann explains:

“When waking up, the brain can maintain the theta rhythm for an extended period, say 5 to 15 minutes, and this time can be used to freely reflect on yesterday's events or what lies ahead in the new day. This period can be very productive and bring many meaningful and creative ideas.”

Is there real evidence that this works?

Seize the moment when your brain is ready to give you best ideas, - a technique that successful people have been followed for hundreds of years.

Artists, writers and great thinkers have long noticed that those moments when we “nod off” - that is, precisely when the theta rhythm predominates in the brain - best time to awaken creativity.

Albert Einstein and Thomas Edison had a habit of solving complex problems while half asleep. A fast, creative mind is built for problem solving, which is why even briefly reflecting on the day's challenges early in the morning while you're still in that state (or even at night as you're starting to fall asleep) can produce amazing results. What worked for Einstein may work for you - although we don't promise you'll become an author. new theory relativity.

How to use your theta rhythm?

It will take some time. But if you do this practice regularly, you will have good habit which will boost your productivity by new level. Here's what you need for this:

1. Select a task

In the morning, when you have already begun to wake up, but your eyes are still closed and your brain is still half asleep, think about the most pressing problem or task that you will face today. Maybe it will be a tricky conversation, an important negotiation with a client, writing a report, or developing a new marketing campaign. But no matter how many tasks are hovering in your mind, you must choose one - and let your brain work on it.

Do not try to somehow direct or limit your thoughts, just make sure that they do not go too far from given topic. Most likely, your brain will unconsciously begin to select a solution.

You'll often end up with a couple of useful ideas. Sometimes it’s even a brilliant insight. Most likely, at first you will forget to use this method every day, but over time it will become another habit, part of your morning rituals.

2. Take notes

Perhaps the most frustrating part of theta problem solving for you is that you will forget those inspired ideas as soon as your head leaves the pillow. You'll be racking your brain in the shower, trying to extract that brilliant three-point plan you just mentally sketched out. That's why you need to write down your resolutions as soon as you're awake enough to open your eyes.

Grab your smartphone (it still charges at the head of the bed, right?) and immediately record your thoughts - in text or on a voice recorder. Don't waste time. Limit yourself to keywords, descriptions, and phrases that will jog your memory later when you are ready to use the information.

An added benefit: the blue light from your phone screen will help you wake up. And if you want to resort to the same method in the evening, while falling asleep, it is better to use a pen and paper - this way artificial light will not disturb your sleep.

3. Analyze the experience

Keep a journal of your "theta thoughts" - over time, this will help you find typical solutions and areas of their application. You may find that this method is most effective for you when solving creative problems, or notice that it gives you an advantage in communicating with people or planning. This will help you understand what problems should be solved using the theta rhythm in the future.

Inspiration can come from anywhere.

But the same is true for obstacles.

Theta Thinking uses the brain's universal problem-solving ability so that you can remember those solutions and use them. It can often help you get around the next obstacle in your path or bridge the gap between a half-baked idea and a truly useful solution, and why not take advantage of that? You don't even have to get out of bed to do this! published