( x^2-7y^3)^2+(x^2+7y^3)^2

Question

( x^2-7y^3)^2+(x^2+7y^3)^2

Answer 1

(x² - 7y³)² + ( x² + 7y³)² = x⁴ - 14x²y³ + y⁶ + x⁴ + 14x²y³ + y⁶ = x⁴ + y⁶ + x⁴ + y⁶ = 2x⁴ + 2y⁶ = 2(x⁴ + y⁶) = 2(x² + y³)²