Answer
$(y-3)(6y-5)$
Work Step by Step
$6y^{2}-23y+15=$
... ... Searching for two factors of $ac=+90$ whose sum is $b=-23,$
we find$\qquad-18$ and $-5.$
Rewrite the middle term and factor in pairs:
$=6y^{2}-18y-5y+15=$
$=6y(y-3)-5(y-3)$
= $(y-3)(6y-5)$