Bonsoir,
5-7 = 5x -3x
- 2 = 2x
x = -2/2
x= -1
7x-2x = -1 -9
5x = -10
x= - 10/5
x= -2
2+3 = 4x+3x
5 = 7x
x= 5/7
7x+5x -3x = 1 +3
9x = 4
x= 4/9
4x-3x +2x = 7 +5
3x= 12
x = 12/3
x= 4
