(2X^2+63y^2)(2x^2-63y^2)
(2x² + 63y²)(2x² - 63y²)
Using FOIL (First, Outside, Inside, Last):
(2x²)(2x²) + (2x²)(-63y²) + (63y²)(2x²) + (63y²)(-63y²)
= 4x4 - 126x²y + 126x²y² - 3969y4
= 4x4 - 3969y4