(x + 3) (x^2 - 3 x + 9) = x^3 - 3 x
3 x + 27 = 0
x^3 + 27 = x (x^2 - 3)
(x + 3) (x^2 - 3 x + 9) = x (x^2 - 3)
x^3 + 27 = x^3 - 3 x
x = -9
(x + 3) (x^2 - 3 x + 9) = x^3 - 3 x
3 x + 27 = 0
x^3 + 27 = x (x^2 - 3)
(x + 3) (x^2 - 3 x + 9) = x (x^2 - 3)
x^3 + 27 = x^3 - 3 x
x = -9