Answer
$(x+6)(x-15)$
Work Step by Step
$x^2-9x-90$ has no common monomial factor
$=(\ \ \ \ \ \ \ \ )(\ \ \ \ \ \ \ \ )$
$=(x\ \ \ \ \ \ )(x\ \ \ \ \ \ )$
$=(x+\ )(x-\ )$ The factors of -90 must have unlike signs.
$=(x+6)(x-15)$ 6 and -15 have a sum of -9 and a product of -90.
