Answer
$2(y-3)(y-15)$
Work Step by Step
$2y^2-36y+90\longrightarrow$ 2 is a common factor.
=2(y^2-18y+45)
=$2(\ \ \ \ \ \ \ \ \ )(\ \ \ \ \ \ \ \ \ )$
=$2(a\ \ \ \ \ \ \ )(a\ \ \ \ \ \ \ )$
=$2(y-\ \ )(y-\ \ )$ Since the 2nd term is negative and the 3rd positive, both factors of 45 must be negative.
=$2(y-3)(y-15)$ -3 and -15 have a sum of -18 and a product of 45.