Найдите корень уравнения 1. 5(2y-9)+6=4(3y-2)-21 2. 5y+7(3-y)=3(5-2y)-6 3. 7y-4(3y+5)=2-3(4y-9)
1.10y-45+6=12y-8-21 10y-45+6-12y+8+21=0 2y=-10 y=-5 2.5y+21-7y=15-6y-6 5y+21-7y-15+6y+6=0 4y=-12 y=-3
3.7y-12y+20-2+12y-27=0. ;7y- 9=0;y=9/7