Answer:
9(x² + 5y⁴) (x² - 5y⁴)
Step-by-step explanation:
9x⁴ - 225y⁸
factor out a 9
9(x⁴ - 25y⁸)
factor (x⁴ - 25y⁸)
(x⁴ - 25y⁸)
x² • x² = x⁴
5y⁴ • -5y⁴ = -25y⁸
(x² + 5y⁴) (x² - 5y⁴)
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