bonjour
a. 7x + 17 = 9x + 29
7 x - 9 x = 29 - 17
- 2 x = 12
x = - 6
b. 4x + 15 = 7x + 24
⇔ 4 x - 7 x = 24 - 15
⇔ - 3 x = 9
⇔ x = - 3
c. 8x + 26 = 5x + 14
⇔ 8 x - 5 x = 14 - 26
⇔ 3 x = - 12
⇔ x = - 4
d. 23x + 31 = 16x + 17
⇔ 23 x - 16 x = 17 - 31
⇔ 7 x = - 14
⇔ x = - 2