Ответ:

12a+31=23a-2

12а-23а=-2-31

-11а=-33

А=-33:(-11)

А=3

2(x-2)-1=5(x-2)-7

2х-4-1=5х-10-7

2х-5х=4+1-10-7

-3х=-12

Х=-12:(-3)

Х=4

4(2y-6)=4y-4

8у-24=4у-4

8у-4у=24-4

4у=20

У=20:4

У=5

-9n+3=3(8n+45)

-9n+3=24n+135

-9n-24n=135-3

-33n=132

N=132:(-33)

N=-4

20+5m=44+m

5m-m=44-20

4m=24

M=24:4

M=6

27-4k=3-8k

8k-4k=3-27

4k=-24

K=-24:4

K=-6

5b+11=7b-3

5b-7b=-3-11

-2b=-14

B=-14:(-2)

B=7

8a+11=4a-1

8a-4a=-1-11

4a=-12

A=-12:4

A=-3

-23(-7z+2)=-529

161z-46=-529

161z=46-529

161z=-483

Z=-483:161

Z=-3

8y+12=12+y

8y-y=12-12

7y=0

Y=0:7

Y=0

6m+7=2+m

6m-m=2-7

5m=-5

M=-5:5

M=-1