Answer:
2·x^3 + 5·x^2 - 8·x - 20 = 0
You see that the term will be 0 for x = 2
(2·x^3 + 5·x^2 - 8·x - 20) / (x - 2) = 2·x^2 + 9·x + 10 = 0
You can use the abc-formula to solve the quadratic equation.
x = -2.5 ∨ x = -2
So the factored form will be
2·x^3 + 5·x^2 - 8·x - 20 = 2·(x - 2)·(x + 2)·(x + 2.5)
