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

Answer: x = { - 2, 2, 3}

Step-by-step explanation:

Using cluster factorization, we write:

x^2 (x - 3) - 4 (x - 3) = 0

(x^2 - 4) (x - 3) = 0

x^2 - 4 = 0 (I) or x - 3 = 0 (II)

(I) x^2 = 4

x = - 2 ou x = 2

(II) x = 3

Therefore, the solution is:

x = - 2; x = 2; x = 3

3x-6x-4x+12=0

-7x+12=0

-7x=-12

X=12/7