Question

13) 5x - (7x + 7) = 9 14) 2x - (6x + 1) = 9 15) 4x - (7x - 2) = 17 16) 2x+7=3x - 2(3x - 1) 17) 4 - 2(x+3)=4(x - 5) 18) 5x+3 =7x - 5(2x+1) 19) Зу - (5 - у) = 11 20) 3x-2 ＿ 2+x 21.9

Answer 1

13) 5x - (7x + 7) = 9

5x - 7x - 7 = 9

2x = 9+7

2x = 16

x = 8

14) 2x - (6x + 1) = 9

2x - 6x - 1 = 9

-4x = 9+1

-4x = 10

x = -2,5

15) 4x - (7x - 2) = 17

4x - 7x + 2 = 17

-3x = 17-2 = 15

x = -5

16) 2x+7=3x - 2(3x - 1)

2x + 7 = 3x - 6x + 2

2x - 3x +6x = 2 - 7

5x = -5

x = -1

17) 4 - 2(x+3)=4(x - 5)

4 - 2x - 6 = 4x - 20

4 - 6 +20 = 4x - 2x

2x = 18

x = 9

18) 5x+3 =7x - 5(2x+1)

5x + 3 = 7x - 10x -5

5x - 7x + 10x = -5 -3

8x = -8

x = -1

19) Зу - (5 - у) = 11

3y - 5 + y = 11

3y + y = 11 - 5

4y = 6

y = 1,5

Answer 2

Let's solve these equations one by one:

13. 5x - (7x + 7) = 9

First, distribute the negative sign:

5x - 7x - 7 = 9

Combine like terms:

-2x - 7 = 9

Now, add 7 to both sides:

-2x = 9 + 7 -2x = 16

Divide by -2 to isolate x:

x = 16 / -2 x = -8

14. 2x - (6x + 1) = 9

Distribute the negative sign:

2x - 6x - 1 = 9

Combine like terms:

-4x - 1 = 9

Add 1 to both sides:

-4x = 9 + 1 -4x = 10

Divide by -4 to isolate x:

x = 10 / -4 x = -2.5

15. 4x - (7x - 2) = 17

Distribute the negative sign:

4x - 7x + 2 = 17

Combine like terms:

-3x + 2 = 17

Subtract 2 from both sides:

-3x = 17 - 2 -3x = 15

Divide by -3 to isolate x:

x = 15 / -3 x = -5

16. 2x + 7 = 3x - 2(3x - 1)

Distribute the -2 on the right side:

2x + 7 = 3x - 6x + 2

Combine like terms:

2x + 7 = -3x + 2

Add 3x to both sides:

2x + 3x + 7 = 2

Combine like terms:

5x + 7 = 2

Subtract 7 from both sides:

5x = 2 - 7 5x = -5

Divide by 5 to isolate x:

x = -5 / 5 x = -1

17. 4 - 2(x + 3) = 4(x - 5)

Distribute on both sides:

4 - 2x - 6 = 4x - 20

Combine like terms:

-2x - 2 = 4x - 20

Add 2x to both sides:

-2 = 6x - 20

Add 20 to both sides:

18 = 6x

Divide by 6 to isolate x:

x = 18 / 6 x = 3

18. 5x + 3 = 7x - 5(2x + 1)

Distribute the -5 on the right side:

5x + 3 = 7x - 10x - 5

Combine like terms:

5x + 3 = -3x - 5

Add 3x to both sides:

8x + 3 = -5

Subtract 3 from both sides:

8x = -5 - 3 8x = -8

Divide by 8 to isolate x:

x = -8 / 8 x = -1

19. Zu - (5 - u) = 11

It appears there's a typographical error in the equation. I'm not sure what "Zu" represents. If it's supposed to be a variable, please provide the correct equation, and I'll be happy to solve it.

20. 3x - 2 * (2 + x) = 21.9

Distribute the -2 on the right side:

3x - 4 - 2x = 21.9

Combine like terms:

x - 4 = 21.9

Add 4 to both sides:

x = 21.9 + 4 x = 25.9