Answer
$(y+6)(y-7)$
Work Step by Step
$y^2-y-42$ has no common monomial factors.
=$(\ \ \ \ \ \ \ \ \ )(\ \ \ \ \ \ \ \ \ )$
=$(y\ \ \ \ \ \ \ )(y\ \ \ \ \ \ \ )$
=$(y+\ \ )(y-\ \ )$ The factors of -42 must have dislike signs.
=$(y+6)(y-7)$ 6 and -7 have a sum of -1 and a product of -42.
