Pomogite reshit' uravneniya(raspisat') 1)8y-3(2y-3)=7y-2(5y+8) 2)5(2y-9)+6y=4(3y-2)-21 3)5y+7(3-y)=3(5-2y)-6 4)7y-4(3y+5)=2-3(4y-9)

1)раскрываем скобки:  
8y-6y+9=7y-10y-16
2y+9=-3y-16
2y+3y=-16-9
5y=-25
y=-5
2)10y-45+6y=12y-8-21
16y-45=12y-29
4y=16
y=4