Explications étape par étape:
b) soit 2x + 3 = 0. 2x = -3 x = -3/2 = -1,5
soit x - 5 = 0. x = 5
c) = (x + 3)² = 0
x + 3 = 0 x = -3
d) (x + 2)(x + 4) - (x + 2)(5x - 8) = 0
(x + 2)(x + 4 - 5x + 8) = 0
(x +2) (-4x + 12) = 0
soit x + 2 = 0 x = -2
soit -4x + 12 = 0 -4x = -12 x = -12/-4 = 3