Решите 4х+2х-7=5; х+3=3х-7 ; 3-х=1+х; 7х+2=3х-10; 2(х-5)=9; 12+3(х-1)=0; -(х+8)=3

Исходное не пишу
6x=5+7
6x=12
x=2

x-3x=-7-3
-2x=-10
x=5

-x-x=1-3
-2x=-2
x=1

7x-3x=-10-2
4x=-12
x=-3

2x-10=8
2x=8+10
2x=18
x=18 : 2
x=9

12+3x-3=0
3x=-9
x=-3

-x-8=3
-x=3+8
-x=11 |·(-1)
x=-11

4x + 2x - 7 = 5 
6x = 12
x = 2 

x+3 = 3x - 7 
2x = 10
x = 5

3-x = 1+x
2x = 2
x = 1 

7x + 2 = 3x - 10
4x = -8
x = 2 

2 (x-5)= 9
2x - 10 = 9
2x = 19 
x = 9,5

12+3 (x-1)=0
15x = 15
x = 1 
-(x+8) = 3 
x = -11