bonjour
2 x + 7 = 8
2 x = 8 - 7
2 x = 1
x = 1/2 = 0.5
3 x - 4 = 2 x + 7
3 x - 2 x = 7 + 4
x = 11
- 6 x + 7 = 3 x - 11
- 6 x - 3 x = - 11 - 7
- 9 x = - 18
x = 2
2.5 x = 3.5 x - 12
2.5 x - 3.5 x = - 12
- x = - 12
x = 12
6 - 5 x = - 7 x + 3
- 5 x + 7 x = 3 - 6
2 x = - 3
x = - 3/2