Question

Решите уравнения пожалуйста
1)3x-5=10-x
2)5x+3(3x+7)=35
3)8y-9-4y+5=12y-4-5y
4)(x-2)(x-1)-x^=5
5)(x+3)(x+7)-(x+4)^=0
6)20x-0,2=0
7)5(x-3)-2(x-7)+7(2x+6)=7

Answer 1

1)
3х+х=10+5
4х=15
х=3,75
2)
5х+3(3х+7)=35
5х+9х+21=35
5х+9х=35-21
14х=14
х=1
3)
8y-9-4y+5=12y-4-5y
8у-4у-12у+5у=9-5-4
-8у=0
у=0
6)
20x-0,2=0
20х=0,2
х=0,01
7)
5(x-3)-2(x-7)+7(2x+6)=7
5х-15-2х+14+14х+42=7
5х-2х+14х=7+15-14-42
17х=-34
х=-2