先化简,再求值:(xx-1-xx2-1)÷x2-xx2-2x+1,其中x是满足不等式组3x-2(x-2)>57-2x2≥1的整数解.-数学

题目简介

先化简,再求值:(xx-1-xx2-1)÷x2-xx2-2x+1,其中x是满足不等式组3x-2(x-2)>57-2x2≥1的整数解.-数学

题目详情

先化简,再求值:(
x
x-1
-
x
x2-1
)÷
x2-x
x2-2x+1
,其中x是满足不等式组
3x-2(x-2)>5
7-2x
2
≥1
的整数解.
题型:解答题难度:中档来源:不详

答案

3x-2(x-2)>5①
class="stub"7-2x
2
≥1②

∵解不等式①得:x>1,
解不等式②得:x≤class="stub"5
2

∴不等式组的解集为:1<x≤class="stub"5
2

∴不等式组的整数解是x=2,
class="stub"x
x-1
-class="stub"x
x2-1
)÷
x2-x
x2-2x+1

=[
x(x+1)
(x+1)(x-1)
-class="stub"x
(x+1)(x-1)
]•
(x-1)2
x(x-1)

=
x2
(x+1)(x-1)
(x-1)2
x(x-1)

=class="stub"x
x+1

当x=2时,原式=class="stub"2
2+1
=class="stub"2
3

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