解:原式=2x³-xyz-2x³+2y³-2xyz+xyz-2y³ =-2xyz当x=-1,y=-2,z=-3时原式=(-2)×(-1)×(-2)×(-3) =12不会还可以再问我,希望采纳,O(∩_∩)O谢谢!
(2x³-xyz)-2(x³-y³+xyz)+(xyz-2y³)=2x³-xyz-2x³+2y³-xyz+xyz-2y³=-xyz=-(-1)*(-2)*(-3)=6
=12