Factor the following problem completely. First, factor out the greatest common factor, and then factor the remaining trinomial:

2r^3 + 8r^2 - 24r

Question

Factor the following problem completely. First, factor out the greatest common factor, and then factor the remaining trinomial:

2r^3 + 8r^2 - 24r

anonymous · Answer

$$ 2r^3 + 8r^2 - 24r = 2r(r^2 + 4r - 12) = 2r(r + 6)(r - 2) $$

anonymous · Answer

I guessed the last step, but it is possible to do it without guessing. Solve $r^2 + 4r - 12 = 0$ to get two roots $r_1$ and $r_2$. $r^2 + 4r - 12$ may then be factored as $(r - r_1)(r - r_2)$.

anonymous · Answer

Correct! Thank you, next question.