Question 460985
{{{x^8-y^8=(x^4)^2-(y^4)^2=(x^4-y^4)(x^4+y^4)=(x^2-y^2)(x^2+y^2)(x^4+y^4)}}}=

={{{(x-y)(x+y)(x^2+y^2)(x^4+y^4)}}}.