Answer:
x = ± 2, x = 3
Step-by-step explanation:
note that x = 2 gives
2³ - 3(2)² - 4(2) + 12 = 8 - 12 - 8 + 12 = 0
Hence x = 2 is a root and (x - 2) is a factor
x³ - 3x² - 4x + 12 ÷ (x - 2)
= (x - 2)(x² - x - 6)
= (x - 2)(x + 2)(x - 3), hence
(x - 2)(x + 2)(x - 3) = 0
equate each factor to zero and solve for x
x - 2 = 0 ⇒ x = 2
x + 2 = 0 ⇒ x = - 2
x - 3 = 0 ⇒ x = 3
