若1x-1y=3,求2x+3xy-2yx+2xy-y的值=______.-数学

题目简介

若1x-1y=3,求2x+3xy-2yx+2xy-y的值=______.-数学

题目详情

1
x
-
1
y
=3
,求
2x+3xy-2y
x+2xy-y
的值=______.
题型:解答题难度:中档来源:不详

答案

class="stub"1
x
-class="stub"1
y
=3
,∴x-y=-3xy,再把它整体代入原式:class="stub"2x+3xy-2y
x+2xy-y
=
2(x-y)+3xy
(x-y)+2xy
=class="stub"-6xy+3xy
-3xy+2xy
=class="stub"-3xy
-xy
=3.
故答案为3.

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