已知1/x-1/y=3 求（2x+3xy-2y)/(x-2xy-y)的值

已知1/x-1/y=3 求（2x+3xy-2y)/(x-2xy-y)的值
已知1/x-1/y=3 求（2x+3xy-2y)/(x-2xy-y)的值

已知1/x-1/y=3 求（2x+3xy-2y)/(x-2xy-y)的值
由已知1/x-1/y=3可得：
y-x=3xy
x-y=-3xy
则：（2x+3xy-2y)/(x-2xy-y)
=(2x-2y+y-x)/[x-y+2/3(x-y)]
=(x-y)/[5/3(x-y)]
=1/5/3
=3/5

五分之三

3/5

1/x-1/y=3
则y-x=3xy
∴（2x+3xy-2y)/(x-2xy-y)
=-3xy/-5xy
=3/5