先合并同类项在求值.5ab-4a^2b^2-8ab^2+3ab-ab^2+4a^2b^2其中a=1,b=-1

先合并同类项在求值.5ab-4a^2b^2-8ab^2+3ab-ab^2+4a^2b^2其中a=1,b=-1
先合并同类项在求值.
5ab-4a^2b^2-8ab^2+3ab-ab^2+4a^2b^2其中a=1,b=-1

先合并同类项在求值.5ab-4a^2b^2-8ab^2+3ab-ab^2+4a^2b^2其中a=1,b=-1
原式=5ab-4a^2b^2-8ab^2+3ab-ab^2+4a^2b^2
=8ab-9ab^2
将a=1,b=-1代入,
则,原式=-8-9=-17.