(x+y+z)的五次方-x的五次方-y的五次方-z的五次方

Question

(x+y+z)的五次方-x的五次方-y的五次方-z的五次方

Answer 1

原式=[(x+y+z)-x][(x+y+z)^4+x(x+y+z)^3+x^2(x+y+z)^2+x^3(x+y+z)+x^4]-(y+z)(y^4-y^3z+y^2z^2-yz^3+z^4)=(y+z)[(x+y+z)^4+x(x+y+z)^3+x^2(x+y+z)^2+x^3(x+y+z)+x^4]-(y+z)(y^4-y^3z+y^2z^2-yz^3+z^4)=(y+z)[(x+y+z)...