Answer
$(y-2)(y-3)(y-1)(y+5)$
Work Step by Step
$y^2-5y+6=y^2-2y-3y+6=y(y-2)-3(y-2)=(y-2)(y-3)$, $y^2-4y-5=y^2-y+5y-5=y(y-1)+5(y-1)=(y-1)(y+5)$, so the GCF is $1$ and the terms that are "not common" are $(y-2),(y-3),(y-1),(y+5)$ so LCD$=(y-2)(y-3)(y-1)(y+5)$
