56x三次方yz+14x三次方y三次方z-21xy三次方z²;

问题描述:

56x三次方yz+14x三次方y三次方z-21xy三次方z²;

56x^3yz+14x^2y^2z-21xy^2z^2
=7xyz(8x^2+2xy-3yz)