1) (5x-3)+(7x-4)=8-(15-11x)
2) 9*(x-4)=405+10x+20
3) (7-5x)-(8-4x)+(5x+6)=8
4) 7*(3-x)-3(x-4)=5*(3+2x)-2*(-3-2x)

Пошаговое объяснение:

1) (5x-3)+(7x-4)=8-(15-11x)

5x - 3 + 7x - 4 = 8 - 15 + 11x

12x - 7 = -7 + 11x

12x - 11x = -7 + 7

x = 0

2) 9*(x-4)=405+10x+20

9x - 36 = 425 + 10x

10x - 9x = -36 - 425

x = -461

3) (7-5x)-(8-4x)+(5x+6)=8

7 - 5x - 8 + 4x + 5x + 6 = 8

4x + 5 = 8

4x = 8 - 5

4x = 3

x = 3:4

x = 0,75

4) 7*(3-x)-3(x-4)=5*(3+2x)-2*(-3-2x)

21 - 7x - 3x + 12 = 15 + 10x + 6 + 4x

-10x + 33 = 14x + 21

14x + 10x = 33 - 21

24x = 12

x = 12 : 24

x = 0,5