Answer:
x = - 4, x = 0, x = 1
Explanation:
To find the zeros equate p(x) to zero, that is
3x³ + 9x² - 12x = 0 ← divide through by 3
x³ + 3x² - 4x = 0 ← factor out x from each term
x(x² + 3x - 4) = 0
x(x + 4)(x - 1) = 0 ← in factored form
Equate each factor to zero and solve for x
x = 0
x + 4 = 0 ⇒ x = - 4
x - 1 = 0 ⇒ x = 1