Question

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)

Answer 1

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

Answer 2

3.7y-12y+20-2+12y-27=0. ;7y- 9=0;y=9/7