Answer:
x = - 2 , x = - 3, x = 3
Step-by-step explanation:
note that x = - 2 gives
(- 2)³ + 2(- 2)² - 9(- 2) - 18 = - 8 + 8 + 18 - 18 = 0
Hence x = - 2 is a zero and (x + 2) is a factor
x³ + 2x² - 9x - 18 ÷ (x + 2)
= (x + 2)(x² - 9 )
to find zeros, equate to zero
(x + 2)(x + 3)(x - 3) = 0
equate each factor to zero and solve for x
x + 2 = 0 ⇒ x = - 2
x + 3 = 0 ⇒ x = - 3
x - 3 = 0 ⇒ x = 3
