Answer:
Step-by-step explanation:
16x⁸ - 81y⁸ is the difference of squares.
16x⁸ - 81y⁸ = (4x⁴)² - (9y⁴)² = (4x⁴ + 9y⁴)(4x⁴ - 9y⁴)
Note that 4x⁴ - 9y⁴ is also the difference of squares.
4x⁴ - 9y⁴ = (2x²) - (3y²)² = (2x² + 3y²)(2x² - 3y²)
16x⁸ - 81y⁸ = (4x⁴ + 9y⁴)(2x² + 3y²)(2x² - 3y²)
