Greatest common factor of the two terms namely x⁴y², - x²y⁴, - x⁴y⁴ of expression x⁴y² - x²y⁴ - x⁴ y⁴ is x²y²

x⁴y² - x²y⁴ - x⁴y⁴ = x²y² (x² - y² -x²y²)