bonjour
3 x + 7 = 0
3 x = - 7
x = - 7 /3
6 - x = 4
- x = 4 - 6
- x = - 2
x = - 2
3 x + 21 = 9
3 x = 9 - 21
3 x = - 12
x = - 4
x - 8 = 0
x = 8
3 x + 7 = x - 1
3 x - x = - 1 - 7
2 x = - 8
x = - 4
3 x + 21 = 4 x + 9
3 x - 4 x = 9 - 21
- x = - 12
x = 12
6 - x = x + 14
- x + x = 14 - 6
0 x = 8 donc pas de solution
2 x - 8 = 7 x - 2
2 x - 7 x = - 2 + 8
- 5 x = 6
x = - 6/5
