jmc

Question

Robert is doing his quadratics factoring worksheet when a drop of ink ruins part of his work.

The problem asks him to factor

- 35 - x + 12 x^{2}

and he has correctly figured out one of two factors:

(3 x + 5) .

What must be the other factor?

Accepted Answer

Given that we have - 35 - x + 12x^2 and the factor 3x + 5, we can guess that the other factor must be 4x - 7 since the linear terms must multiply to 12x^2 and the constant terms must multiply to -35. Expanding, we can verify that this is correct, and therefore our answer is (4x - 7).