问题
解答题
先化简,再求值:(a2b-2ab2-b3)÷b-(a+b)(a-b),其中a=
|
答案
(a2b-2ab2-b3)÷b-(a+b)(a-b),
=a2-2ab-b2-(a2-b2),
=a2-2ab-b2-a2+b2,
=-2ab,
当a=
,b=-1时,1 2
原式=-2×
×(-1)=1.1 2
先化简,再求值:(a2b-2ab2-b3)÷b-(a+b)(a-b),其中a=
|
(a2b-2ab2-b3)÷b-(a+b)(a-b),
=a2-2ab-b2-(a2-b2),
=a2-2ab-b2-a2+b2,
=-2ab,
当a=
,b=-1时,1 2
原式=-2×
×(-1)=1.1 2