①计算:|-1|-4+(π-3)0+2-2②解方程:xx+3=1x-2+1③先化简,再求值:x2-2xx2-1÷(x-1-2x-1x+1),其中x=12.-数学

题目简介

①计算:|-1|-4+(π-3)0+2-2②解方程:xx+3=1x-2+1③先化简,再求值:x2-2xx2-1÷(x-1-2x-1x+1),其中x=12.-数学

题目详情

①计算:|-1|-
4
+(π-3)0+2-2

②解方程:
x
x+3
=
1
x-2
+1

③先化简,再求值:
x2-2x
x2-1
÷(x-1-
2x-1
x+1
)
,其中x=
1
2
题型:解答题难度:中档来源:不详

答案

①|-1|-
4
+(π-3)0+2-2
=1-2+1+class="stub"1
4

=class="stub"1
4

class="stub"x
x+3
=class="stub"1
x-2
+1

方程可化为x2-2x=x2+2x-3
解得x=class="stub"3
4

经检验x=class="stub"3
4
是方程的根.
x2-2x
x2-1
÷(x-1-class="stub"2x-1
x+1
)

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

=class="stub"1
x-1

当x=class="stub"1
2
时,原式=-2.

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