(a²b-2ab²-b³)÷b-(a+b)(a-b)其中a=1/2 b=-1

问题描述:

(a²b-2ab²-b³)÷b-(a+b)(a-b)其中a=1/2 b=-1

原式=a²-2ab-b²-(a²-b²)
=a²-2ab-b²-a²+b²
=-2ab
=-2×1/2×(-1)=1