Turn the equation into factored form
y=x^3+3x^3-6x-8

Y = x³ + 3x² - 6x - 8, to get the factored form put y = 0,
x³ + 3x² - 6x - 8 = 0, x³ + x² + 2x² + 2x - 8x - 8 = 0, 
x²(x + 1) + 2x(x + 1) - 8(x + 1) = 0,
(x + 1)(x² + 2x - 8) = 0, (x + 1)(x² + 4x - 2x -8) = 0, 
(x + 1)(x[x + 4] - 2[x +4]) = 0, 
(x +1)(x +4)(x - 2) = 0, this is the factored form.
x = -1, -4, 2.