Réponse :
.12x - 11 = 37
12x = 37 + 11
12x = 48
x = 48/12
x = 4
.9 = 7x - 19
9 + 19 = 7x
28 = 7x
x = 28/7
x = 4
. 2x + 17 = 5x + 2
2x - 5x +17 = 5x - 5x +2
-3x + 17 = 2
-3x + 17 - 17 = 2 - 17
-3x = -15
x = -15/-3
x = 5
. 9x - 3 = 7x + 5
9x - 7x -3 = 7x - 7x +5
2x -3 = 5
2x = 5 + 3
2x = 8
x = 8/2
x = 4
Explications étape par étape