Question

$x {4} - 81y {4}$
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Answer 1

Answer:

(x² + 9y²)(x - 3y)(x + 3y)

Step-by-step explanation:

x⁴ - 81y⁴

(x²)² - (9y)²

a² - b² = (a + b)(a - b)

(x² - 9y²)(x² + 9y²)

(x² +9y²)(x² -  (3y)²)

Again use: a² - b² = (a + b)(a - b)

(x² + 9y²)(x - 3y)(x + 3y)