bonsoir
résoudre 18-3x=5x
18 = 5x + 3x
18 = 8x
x = 18/8
x = (2 * 9)/(2 * 4)
x = 9/4
18 - 3 x = 5 x
- 3 x - 5 x = - 18
- 8 x = - 18
x = 18/8 = 9 /4