Verified answer

Bonsoir,

f(x) = x[x - 1 + 2(x - 3)]

f(x) = x(x - 1 + 2x - 6)

f(x) = x(3x - 7)

g(x) = (x - 1)[x - 1 + 4(x + 5)]

g(x) = (x - 1)(x - 1 + 4x + 20)

g(x) = (x - 1)(5x + 19)

h(x) = (x + 5 - 2x - 7)(x + 5 + 2x + 7)

h(x) = (-x - 2)(3x + 12)

h(x) = -3(x + 2)(x + 4)

f(-3) = -3(3 * -3 - 7)

f(-3) = -3(-9 - 7)

f(-3) = -3 * -16

f(-3) = 48

g(3/7) = (3/7 - 1)(5 * 3/7 + 19)

g(3/7) = (3/7 - 7/7)(15/7 + 133/7)

g(3/7) = (-4/7) * 148/7

g(3/7) = -592/49

h(x) = 0

Un produit de facteur est nul si et seulement si au moins un de ses facteurs est nul

x + 2 = 0 ou x + 4 = 0

x = -2 ou x = -4