Answer:
w = 0 , -3 , 3
Step-by-step explanation:
w³ - 9w = 0
w(w² - 9) = 0
w(w² - 3²) = 0
w(w+3)(w-3) = 0 {a² - b² = (a + b)(a - b) }
w = 0 ; w + 3 = 0 ; w - 3 = 0
w = -3 ; w = 3
