Réponse :
Bonsoir
Explications étape par étape :
A)
7x + 15 = 6x + 3
7x - 6x = 3 - 15
X = -12
B)
-1x/3 + 3 = 2x/3 - 2
-1x/3 - 2x/3 = -2 - 3
-3x/3 = -5
-x = - 5
X = 5
C)
3.2 + 8x = 9x - 5.1
8x - 9x = -5.1 - 3.2
- x = - 8.3
X = 8.3
D)
0.9x - 4 = - 0.1x - 6
0.9x + 0.1x = - 6 + 4
X = -2