已知1/x-1/y=2,求2x+5xy−2yx−2xy−y=_.

问题描述:

已知

1
x
-
1
y
=2,求
2x+5xy−2y
x−2xy−y
=______.

1
x
-
1
y
=-
x−y
xy
=2,即x-y=-2xy,
∴原式=
2(x−y)+5xy
x−y−2xy
=
−2xy+5xy
−2xy−2xy
=-
3
4

故答案为:-
3
4