text: Rearrange them to x^3 + 3x^2 -4x -12 = 0\n\nThen group the first 2 and the second 2\n\n(x^3+3x^2) + (-4x - 12) = 0\n\nFrom the first group, you can pull out x^2; from the second group, you can pull out -4\n\nx^2*(x+3) -4*(x+3) = 0\n\nNow you can pull out (x+3)\n\n(x+3)(x^2-4) = 0 --- now x^2 - 4 is a difference of squares, which are factored a^2-b^2=(a+b)(a-b) so you can factor x^2-4 even further\n\n(x+3)(x+4)(x-4)=0