Question

x⁴ + 4y⁴

Answer 1

\(x^4+4y^4\\ =\left(x^2\right)^2+\left(2y^2\right)^2+4x^2y^2-4x^2y^2\\ =\left[\left(x^2\right)^2+\left(2y^2\right)^2+4x^2y^2\right]-4x^2y^2\\ =\left(x^2+2y^2\right)^2-4x^2y^2\\ =\left(x^2+2y^2-2xy\right)\left(x^2+2y^2+2xy\right)\)