Question

x^2y-y^2z+xz^2-x^2z+xy^2+yz^2-2xyz

Answer 1

x^2y-y^2z+xz^2-x^2z+xy^2+yz^2-2xyz

=（x² y-x² z）+(xz²+xy²-2xyz)-(y² z-yz²)

=x²(y-z)+x(y²-2yz+z²)-yz(y-z)

=x²(y-z)+x(y-z)²-yz(y-z)

=(y-z)[x²+x(y-z)-yz]

=(y-z)(x+y)(x-z)