Question

Решите уравнения: 1) х+ 4/21 = 2/3+2/7. 2) у+1/4=4/5-3/10. 3) ( 4/5-х) +13/20=7/10 4) 2/3-(2/9+х)=1/3. помогите пожалуйста срочно!!!!

Answer 1

Х + 4/21=2/3+2/7
х+4/21=1421+6/21
х+4/21-14/21-6/21=0(*21)
х+4-14+6=0
х-10+6=0
х-4=0
х=4

Answer 2

Solving Equations:

Sure, I can help you solve these equations. Let's go through each one step by step:

1) x + 4/21 = 2/3 + 2/7:

To solve this equation, we need to isolate the variable x. We can start by getting rid of the fractions by finding a common denominator. In this case, the common denominator is 21.

Multiplying both sides of the equation by 21, we get:

21(x) + 4 = 14 + 6

Simplifying the equation, we have:

21x + 4 = 20

Next, we can isolate x by subtracting 4 from both sides:

21x = 20 - 4

21x = 16

Finally, we divide both sides by 21 to solve for x:

x = 16/21

Therefore, the solution to the equation is x = 16/21.

2) y + 1/4 = 4/5 - 3/10:

To solve this equation, we can start by finding a common denominator for the fractions. In this case, the common denominator is 20.

Multiplying both sides of the equation by 20, we get:

20(y) + 5 = 16 - 6

Simplifying the equation, we have:

20y + 5 = 10

Next, we can isolate y by subtracting 5 from both sides:

20y = 10 - 5

20y = 5

Finally, we divide both sides by 20 to solve for y:

y = 5/20

Simplifying the fraction, we have:

y = 1/4

Therefore, the solution to the equation is y = 1/4.

3) (4/5 - x) + 13/20 = 7/10:

To solve this equation, we can start by simplifying the left side of the equation:

4/5 - x + 13/20 = 7/10

Next, we can find a common denominator for the fractions. In this case, the common denominator is 20.

Multiplying both sides of the equation by 20, we get:

16 - 20x + 13 = 14

Simplifying the equation, we have:

-20x + 29 = 14

Next, we can isolate x by subtracting 29 from both sides:

-20x = 14 - 29

-20x = -15

Finally, we divide both sides by -20 to solve for x:

x = -15/-20

Simplifying the fraction, we have:

x = 3/4

Therefore, the solution to the equation is x = 3/4.

4) 2/3 - (2/9 + x) = 1/3:

To solve this equation, we can start by simplifying the expression inside the parentheses:

2/3 - 2/9 - x = 1/3

Next, we can find a common denominator for the fractions. In this case, the common denominator is 9.

Multiplying both sides of the equation by 9, we get:

6 - 2 - 9x = 3

Simplifying the equation, we have:

4 - 9x = 3

Next, we can isolate x by subtracting 4 from both sides:

-9x = 3 - 4

-9x = -1

Finally, we divide both sides by -9 to solve for x:

x = -1/-9

Simplifying the fraction, we have:

x = 1/9

Therefore, the solution to the equation is x = 1/9.

I hope this helps! Let me know if you have any further questions.