9. 2x - 5 = 7(3x + 4) + 5
10. 28 - 4(3x + 2) = 5(2x - 7)
11. 3x - 4(5x + 2) - 6(3x - 4) = 1
12. 7(x - 4) + 3 = - 5(2x - 7) + х - 8

9) 2х-5=7(3х+4)+5

2х-5=21х+28+5

2х-21х=28+5+5

-19х=38

х=38:(-19)

х=-2

10) 28-4(3х+2)=5(2х-7)

28-12х-8=10х-35

12х-10х=-35-28+8

-2х=1

х=-0,5

11) 3х-4(5х+2)-6(3х-4)=1

3х-20х-8-18х+24=1

3х-20х-18х=1+8-24

0х=-15

нет корней

12) 7(х-4)+3=-5(2х-7)+х-8

7х-28+3=-10х+35+х-8

7х+10х-х=35-8+28-3

16х=52

х=52:16

х=31/4