5x + (7.5+3x)=5x+2 -3x+7(2-3x)=-4x-5 -8x + 2(9+7x)=5x-10 5x+4(7+4x)=-4x+4

-5х + (7.5+3х)=5х+2
-5х + 7.5+3х=5х+2
-5х +3х -5х= 2-7.5
-7х=-4.5
х=4.5/7

-3х+7(2-3х) = -4х-5
-3х+14-21х=-4х-5
-3х-21х+4х= -5-14
-20х=-19
х=0.95

-8х+2(9+7х)=5х-10
-8х+18+14х=5х-10
6х-5х= -28
х=-28

5х+4(7+4х)=-4х+4
5х+28+16х=-4х+4
21х+4х=4-28
25х=-24
х=-0.96