Answer
$2(x+3)(x-6)$
Work Step by Step
$2x^2-6x-36\longrightarrow$ 2 is a common factor.
=$2(x^2-3x-18)$
=$2(\ \ \ \ \ \ \ \ \ )(\ \ \ \ \ \ \ \ \ )$
=$2(x\ \ \ \ \ \ \ )(x\ \ \ \ \ \ \ )$
=$2(x+\ \ )(x-\ \ )$ The factors of -18 must have unlike signs.
=$2(x+3)(x-6)$ 3 and -6 have a sum of -3 and a product of -18.