计算:(1)x+1-x2x+1;(2)先化简,再求值:b2-a2a2b-ab2÷(1+a2+b22ab),其中a=-2,b=3.-数学

题目简介

计算:(1)x+1-x2x+1;(2)先化简,再求值:b2-a2a2b-ab2÷(1+a2+b22ab),其中a=-2,b=3.-数学

题目详情

计算:
(1)x+1-
x2
x+1

(2)先化简,再求值:
b2-a2
a2b-ab2
÷(1+
a2+b2
2ab
)
,其中a=-2,b=3.
题型:解答题难度:中档来源:不详

答案

(1)原式=
(x+1)2
x+1
-
x2
x+1
=class="stub"2x+1
x+1

(2)原式=
(b+a)(b-a)
ab(a-b)
÷
2ab+a2+b2
2ab

=-class="stub"a+b
ab
×class="stub"2ab
(a+b)2

=-class="stub"2
a+b

∵a=-2,b=3,
∴原式=-class="stub"2
a+b

=-class="stub"2
-2+3

=-2.

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