Pomogite reshit'...

Question

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)

Answer 1

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