求当a=﹣2分之1,b=1时,代数式2a²b{2ab²-2(a²b+2ab²)}的值.

问题描述:

求当a=﹣2分之1,b=1时,代数式2a²b{2ab²-2(a²b+2ab²)}的值.

2a²b+{2ab²-2(a²b+2ab²)}
=2a²b+2ab²-2a²b-4ab²
=-2ab²
=-2x(-1/2)x1²
=1