箱变分类国标:分式的能力拓展(帮个忙啊~~~)

来源:百度文库 编辑:高考问答 时间:2024/05/02 00:38:16
已知1/x-1/y=3,求分式(2x+3xy-2y)/(x-2xy-y)的值.

由1/X-1/Y=3得(Y-X)/XY=3得X+3XY-Y=0
(2X+3XY-2Y)/(X-2XY-Y)=[2(X+3XY-Y)-3XY]/[(3XY+X-Y)-5XY]
=(-3XY)/(-5XY)=3/5=0.6