Bonjour
a. (2x + 1) (4x - 1) = 0
2x + 1 = 0 ou 4x - 1 = 0
2x = - 1 4x = 1
x = - 1/2 x = 1/4
b. (2x - 9) (- x - 2) = 0
2x - 9 = 0 ou - x - 2 = 0
2x = 9 - x = 2
x = 9/2 x = - 2
c. (3x - 5) (8 - 2x) = 0
3x - 5 = 0 ou 8 - 2x = 0
3x = 5 - 2x = - 8
x = 5/3 x = 8/2 = 4
d. (10 - 4x) * 7 = 0
70 - 4x = 0
- 4x = - 70
x = 70/4
x = 17,5.