Question

Which equation is equivalent to x^4-y^4

Answer 1

x⁴ - y⁴
x⁴ - x²y² + x²y² - y⁴
x²(x²) - x²(y²) + y²(x²) - y²(y²)
x²(x² - y²) + y²(x² - y²)
(x² + y²)(x² - y²)