To simplify the expression "a^2 - 16 / (a + 4)," you can factor the numerator and denominator and then cancel out any common factors.
1. First, factor the numerator:
a^2 - 16 can be factored as (a + 4)(a - 4).
2. Now, rewrite the expression:
(a + 4)(a - 4) / (a + 4)
3. Next, cancel out the common factor of (a + 4) in the numerator and denominator:
(a - 4) / 1
So, the simplified result is just "a - 4."