>>944
x{(y-z)^5}+y{(z-x)^5}+z{(x-y)^5}
= (x-y)(y-z)(z-x)(x^3 +y^3 +z^3 +(x^2)y+x(y^2)+(y^2)z+y(z^2)+(z^2)x+z(x^2)-9xyz)