问题
解答题
(1)计算:
(2)先化简,再求值:(a2b-2ab2-b3)÷b-(a+b)(a-b),其中a=
|
答案
(1)原式=6×
+2-1 3
+13
=5-
.3
(2)原式=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
(1)计算:
(2)先化简,再求值:(a2b-2ab2-b3)÷b-(a+b)(a-b),其中a=
|
(1)原式=6×
+2-1 3
+13
=5-
.3
(2)原式=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