Réponse :
bonsoir
a) x +6 = 2 x - 1
x- 2 x = - 1 - 6
- x = - 7
x = 7
b ) 18 x + 54 = 4
18 x = 4 - 54
18 x = - 50
x = - 50/18 = - 25 / 9
c) - 3 x + 12 = 2 x
- 3 x - 2 x = - 12
- 5 x = - 12
x = 12/5
d) 2 x + 1 = x - 1
2 x - x = - 1 - 1
x = - 2
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