求当a=-1/2,b=1时,代数式2a²b-【2ab²-2(a²b+2ab²)】的值

问题描述:

求当a=-1/2,b=1时,代数式2a²b-【2ab²-2(a²b+2ab²)】的值
求当a=-1/2,b=1时,代数式2a²b-【2ab²-2(a²b+2ab²)】的值

2a²b-【2ab²-2(a²b+2ab²)】=2a²b-2ab²+(2a²b+2ab²)=2a²b-2ab²+2a²b+2ab²=4a²b=4×(-1/2)²×1=1