What are the real zeros of this function. x^3+2x^2-9x-18

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