Question

因式分解x四次方加x平方y平方加y四次方

Answer 1

x^4+x^2y^2+y^4
(x^4+2x^2y^2+y^4)-x^2y^2
=(x^2+y^2)^2-x^2y^2
=(x^2+y^2+xy)(x^2+y^2-xy)