Ответ:

1)-5y+8= 5-2y

-5y+2y= 5-8

-3y= -3

3y=3

y=3:3

y=1

2)5-11b=7b-13

-11b-7b= -13-5

-18b= -18

18b= 18

b= 18:18

b= 1

3)-15y-7= 2y+10

-15y-2y= 10+7

-17y= 17

17y= -17

y= -17:17

y= -1