Explications étape par étape:
a. 8x + 3 = 0
8x = 0 - 3
8x = -3
x = -3/8 (noté en fraction)
b. 2x - 9 = 0
2x = 0 - 9
2x = -9
x = -9/2
c. 49 - 7x = 0
-7x = - 49
x = -49/-7
x = 7
d. -6x - 5 = 0
-6x = 0 + 5
-6x = 5
x = 5/-6
e. 5x + 12 = 3
5x = 3 - 12
5x = -9
x = -9/5
f. 10x + 1 = -7
10x = -7 - 1
10x = -8
x = -8/10
g. 9x - 2 = 6
9x = 6 + 2
9x = 8
x = 8/9
h. 20 - 4x = -4
- 4x = -4 - 20
-4x = -24
x = -24/-4
x = 6
Voilà, si tu as des questions n'hésite pas