Answer
$4(x+2)(x-2)$
Work Step by Step
Step 1: $4x^{2}-16$
Step 2: Both terms have a common factor of $4$, which is factored out:
$4x^{2}-16=4(x^{2}-4)$.
Step 3: $4(x^{2}-4)$ can be further factored into
$4(x^{2}-4)=4(x+2)(x-2)$.
Step 4: No further factorization possible.