Answer
$a. (x+4)(x-4)$
Work Step by Step
The lowest common denominator for this problem can be found by comparing the three denominators.
1. $(x-4)$
2. $(x+4)(x-4)$ [which is $(x^{2}-16)$ factored]
3. $(x+4)$
If we multiply the first denominator by $(x+4)$ and third denominators by $(x-4)$ we will arrive at a LCD of $(x+4)(x-4)$.
