1/2m·mn·m-m·n·m²+1/2m²·n·m 化简
问题描述：
1/2m·mn·m-m·n·m²+1/2m²·n·m 化简
答
解=1/2m^2.n.m+1/2m^2.n.m-m.n.m^2
=m^2.n.m-m^2.n.m
=0