Answer
$x(x+12)(x-13)$
Work Step by Step
$x^3-x^2-156x\longrightarrow$ x is a common factor.
$x(x^2-x-156)$
=$x(\ \ \ \ \ \ \ \ \ )(\ \ \ \ \ \ \ \ \ )$
=$x(x\ \ \ \ \ \ \ )(x\ \ \ \ \ \ \ )$
=$x(x+\ \ )(x+\ \ )$ The factors of -156 must have unlike signs.
=$x(x+12)(x-13)$ 12 and -13 have a sum of -1 and a product of -156.
