Question

Помогите решить: 1) 5-4x=x+20 2) 3x-7= -x+5 3) 5x-2*(2x-1)=-2 4) 3(2x+7)+4=5(x-3)

Answer 1

$1)5 - 4x = x + 20 \\ - 4x - x = 20 - 5 \\ - 5x = 15 \\ x = - \frac{15}{5} = - 3 \\ 2)3x - 7 = - x + 5 \\ 3x + x = 5 + 7 \\ 4x = 12 \\ x = \frac{12}{4} = 3 \\ 3)5x -4x + 2 = - 2 \\ x = - 4 \\ 4)6x + 21 + 4 = 5x - 15 \\ 6x - 5x = - 15 - 21 - 4 \\ x = - 40$

Answer 2

1)
5-4х=х+20
-4х-х=20-5
-5х=15
х=-3

2)
3х-7=-х+5
3х+х=5+7
4х=12
х=3

3)
5х-2*(2х-1)=-2
5х-4х+2=-2
х+2=-2
х=-2-2
х=-4

4)
3(2х+7)+4=5(х-3)
6х+21+4=5х-15
6х+25=5х-15
6х-5х=-15-25
х=-40