Answer:
(25x^2 + 9) (5x + 3) (5x - 3).
Explanation:
Rewrite 625
as (25x²)².
(25x²)² - 81
Rewrite 81 as 9².
(25x²)² - 9²
Since both terms are perfect squares, factor using the difference of squares formula, a² − b² = (a+b) (a−b) where a = 25x² and b = 9.
(25x² + 9) (25x² - 9)
Simplify we get.
(25x² + 9) (5x + 3) (5x - 3)