Question

factor
16 - y²

Explanation:

Step1: Recognize difference of squares

$16-y^2 = 4^2 - y^2$

Step2: Apply difference of squares formula

Use $a^2 - b^2 = (a+b)(a-b)$, where $a=4$, $b=y$
$4^2 - y^2 = (4+y)(4-y)$

Answer:

$(4 + y)(4 - y)$