已知:A=2a²+3ab-b²,B=-1/2ab,C=1/8a³b³-1/4a²b^4,求2A*B²-C.

题目

已知:A=2a²+3ab-b²,B=-1/2ab,C=1/8a³b³-1/4a²b^4,求2A*B²-C.

答案

2A*B²-C=2(2a²+3ab-b²)×(-1/2ab)²-(1/8a³b³-1/4a²b^4)=2(2a²+3ab-b²)×1/4a²b²-(1/8a³b³-1/4a²b^4)=a^4b²+3a³b³/2-a²...