化简(x-2-y-2)÷(x-1+y-1)的结果是()A.yxB.y-xxyC.x+yxyD.xyx-y-数学

题目简介

化简(x-2-y-2)÷(x-1+y-1)的结果是()A.yxB.y-xxyC.x+yxyD.xyx-y-数学

题目详情

化简(x-2-y-2)÷(x-1+y-1)的结果是(  )
A.
y
x
B.
y-x
xy
C.
x+y
xy
D.
xy
x-y
题型:单选题难度:中档来源:不详

答案

原式=(class="stub"1
x2
-class="stub"1
y2
)÷(class="stub"1
x
+class="stub"1
y

=
y2-x2
x2y2
÷class="stub"y+x
xy

=
(y+x)(y-x)
(xy)2
class="stub"xy
y+x

=class="stub"y-x
xy

故选:B.

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