分类：教育/科学-学习帮助
问题：初二已知(1/x)
已知(1/x)-(1/y)=2,求(2x+3xy-2y)/(x-2xy-y)
回答：(1/x)-(1/y)=2
(y-x)/xy=2   [通分]
y-x=2xy
(2x+3xy-2y)/(x-2xy-y)
=[2(x-y)+3xy]/[(x-y)-2xy]
=(-4xy+3xy)/(-2xy-2xy)
=-xy/-4xy
=1/4