Answer:
(5n + 4)(5n - 4)
Explanation:
This is the difference of perfect squares. It follows a pattern of
(ax + b)(ax - b) where a is the square root of 25 and b is the square root of 16. The square root of 25 is 5, the square root of 16 is 4, so our factored quadratic is
(5n + 4)(5n - 4)