Bonjour
1) x + 18 = -40
x = - 40 - 18
x = - 58
2) 72 - x = 94
- x = 94 - 72
- x = 22
x = - 22
3) -7x = 28
x = - 28/7 = - 4
4) x sur 9 = -5
x = - 45
5) 14x + 3 = -15
14 x = - 15 - 3
14 x = - 18
x = - 9/7
6) 6 - 15x = 11
- 15 x = 11 - 6
- 15 x = 5
x = - 5/15 = - 1 /3
7) 30x - 10 = 20x + 70
30 x - 20 x = 70 + 10
- 10 x = 80
x = - 8
8) 20 - 2x = 6x - 36
- 2 x - 6 x = - 36 - 20
- 8 x = - 56
x = 7