## College Algebra (6th Edition)

$2(x+7)(x-8)$
$2x^{2}-2x-112$ Factor out common factor 2 from the expression. $2(x^{2}-x-56)$ Since the last term of $(x^{2}-x-56)$ is -56. We need to find two factors of -56 that have a sum of -1. 7 and -8 are factors of -56. Also, $7\times-8=-56$ and $7-8=-1$ Therefore, $2(x^{2}-x-56)$ can be written as $=2(x^{2}+7x-8x-56)$ Group the terms. $=2((x^{2}+7x)+(-8x-56))$ Factor out common factors. $=2(x(x+7)-8(x+7))$ Factor out common factor (x+7). $=2((x+7)(x-8))$