Factor by using the difference of two squares formula.
x^2-16
The difference of two squares formula states that the difference of two perfect square terms can be factored as (a^2 - b^2) = (a + b)(a - b).
In this case, we have x^2 - 16, which can be written as (x^2 - 4^2).
Using the difference of two squares formula, we can factor it as follows:
(x^2 - 4^2) = (x + 4)(x - 4).
Therefore, the expression x^2 - 16 can be factored as (x + 4)(x - 4).