Answer
$$(2y-3)(2y-5) .$$
Work Step by Step
First, for the polynomial $4y^2 - 16y + 15$, we write
$$4y^2 - 16y + 15=4y^2 - 6y-10y + 15 .$$
By grouping the first two terms and the second two terms and then taking common factors, we have
$$4y^2 - 6y-10y + 15=2y(2y-3)-5(2y-3)=(2y-3)(2y-5) .$$
