6у=-18, -2x=-6+x,7z-z+5=11,-3(4x-8)=3x-6,x+3x=160

6у = - 18
у = - 18 : 6
у = - 3

- 2х = - 6 + х
- 2х - х = - 6
- 3х = - 6
х = - 6 : 3
х = - 2

7z - z + 5 = 11
6z + 5 = 11
6z = 11 - 5
6z = 6
z = 6 : 6
z = 1

- 3 * (4х - 8) = 3х - 6
- 12х + 24 = 3х - 6
- 12х - 3х = - 6 - 24
- 15х = - 30
х = - 30 : 15
х = - 2

х + 3х = 160
4х = 160
х = 160 : 4
х = 40

6y=-18
y=-18:6
y=-3

-2х=-6+х
-2х-х=-6
-3х=-6
х=-6:(-3)
х=2

7z-z+5=11
7z-z=11-5
6z=6
z=6:6
z=1

-3(4x-8)=3x-6
-12x+24=3x-6
-12x-3x=-6-24
-15x=-30
x=-30:(-15)
х=2

х+3х=160
4х=160
х=160:4
х=40