Answer
$$(y+6)(y-6)$$
Work Step by Step
$y^{2}-36$
This is the difference between two squares.
There is a simple formula for this case:
$x^{2}-y^{2}=(x+y)(x-y)$
So, applying this formula,
We need to take the square of both terms.
$\sqrt y^{2}=y$
$\sqrt 36=6$
So the answer would look like:
$$(y+6)(y-6)$$
(One with a positive sign and one with a negative sign.)
