Answer
$$(cd+4)(cd-4)$$
Work Step by Step
$c^{2}d^{2}-16$
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.
$\sqrt (c^{2}d^{2})=cd$
$\sqrt 16=4$
So the answer would look like:
$$(cd+4)(cd-4)$$
(One with a positive sign and one with a negative sign.)
