Question 852034
{{{256-y^8x^8=(16-x^4y^4)(16+x^4y^4)}}}
{{{256-y^8x^8=(4-x^2y^2)(4+x^2y^2)(16+x^4y^4)}}}
{{{256-y^8x^8=(2-xy)(2+xy)(4+x^2y^2)(16+x^4y^4)}}}