Question

分式问题

已知1/x-1/y=3，求分式(2x+3xy-2y)/(x+2xy-y)的值
没有错啊！

Answer 1

1/x-1/y=3
(y-x)/xy=3
(y-x)=3xy
所以:(2x+3xy-2y)/(x+2xy-y)
=(2(x-y)+3xy)/((x-y)+2xy)
=(-6xy+3xy)/(-3xy+2xy)
=-3xy/(-xy)
=3

Answer 2

你出错了

Answer 3

因为1/x-1/y=3，
所以y/(xy)-x/(xy)=3,
所以(y-x)/(xy)=3,
所以y-x=3xy,
所以(2x+3xy-2y)/(x+2xy-y)
=[-2(y-x)+3xy]/[-(y-x)+2xy]
=(-2*3xy+3xy)/(-3xy+2xy)
=-3xy/(-xy)
=3.