8у-3(2у-3)=7у-2(5у+8)=
8у-3(2у-3)=7у-2(5у+8)
8y-6y+9=7y-10y-16
8y-6y-7y+10y=-9-16
5y=-25
y=-5
уже поздно
8y-3(2y-3)=8y-6y+9=2y+9 7y-2(5y+8)=7y-10y-16=-3y-16