Answer
$(y+8)(y-9)$
Work Step by Step
$y^2-y-72$ has no common monomial factors.
=$(\ \ \ \ \ \ \ \ \ )(\ \ \ \ \ \ \ \ \ )$
=$(y\ \ \ \ \ \ \ )(y\ \ \ \ \ \ \ )$
=$(y+\ \ )(y-\ \ )$ The factors of -72 must have unlike signs.
=$(y+8)(y-9)$ 8 and -9 have a sum of -1 and a product of -72.
