A=-1/2x 3x2-x3,B=2(x3 x2-1/2x-1),求1/2(A B)-1/3(A-B)的值

问题描述:

A=-1/2x 3x2-x3,B=2(x3 x2-1/2x-1),求1/2(A B)-1/3(A-B)的值