Sagot :
bonsoir
12 x + 15 = 6 x + 3
12 x - 6 x = 3 - 15
6 x = - 12
x = - 2
5 x - 3 = 2 x + 4
5 x - 2 x = 4 + 3
3 x = 7
x = 7 /3
- 7 x - 8 = - 10 x + 4
- 7 x + 10 x = 4 + 8
3 x = 12
x = 4
2 x + 7 = 9 x - 5
2 x - 9 x = - 5 - 7
- 7 x = - 12
x = 12/7
A ) 12x + 15 = 6x + 3
12x - 6x = 3 - 15
6x = -12
x= -12/6
x = -2
B) 5x - 3 = 2x +4
5x - 2x = 4 + 3
3x = 7
x = 7/3
C) -7x -8 = -10x + 4
-7x + 10x = 4+ 8
3x = 12
x= 12/3
x= 4
D ) 2x + 7 = 9x - 5
2x - 9x = -5 -7
-7x = -12
x = -12/-7
x = 12/7
12x - 6x = 3 - 15
6x = -12
x= -12/6
x = -2
B) 5x - 3 = 2x +4
5x - 2x = 4 + 3
3x = 7
x = 7/3
C) -7x -8 = -10x + 4
-7x + 10x = 4+ 8
3x = 12
x= 12/3
x= 4
D ) 2x + 7 = 9x - 5
2x - 9x = -5 -7
-7x = -12
x = -12/-7
x = 12/7