3x^3+x^2-12x-4=0

Answer 1

I assume we are solving ??

x^2(3x+1) - 4(3x + 1) = 0
(3x+1)(x^2 - 4) = 0
(3x+1)(x+2)(x-2) = 0
x = -1/3, -2, 2