Bonjour,
3x -2x = -5 -2
x = -7
2x+3x = 17 -7
5x = 10
x= 10/5
x= 2
-11 -13 = 3x+3x
-24 = 6x
6x = -24
x = -24/6
x= -4
7x-4x = 9+2
3x = 11
x = 11/3
5-2 = -4x+5x
3 = x
x=3
-3x+3x+ 15 +9
x= 24
3a+5a = 6 +12
8a = 18
a = 18/8
a =9/4
4a-2a =-12 +12
2a= 0
a = 0
