Question

有关于分式的题……急急急！

已知1/x-1/y=5，求3x+5xy-3y/x-y-3xy的值。
求详解。

Answer 1

1/x-1/y=5可划为 y-x=5xy 即 x+y=-5xy 那么 3x+5xy-3y/x-y-3xy=3(x+y)+5xy/-5xy-3xy
=-10xy/-8xy=5/4

Answer 2

1/x-1/y=5
(y-x)/xy=5
y-x=5xy
x-y=-5xy

3x+5xy-3y/x-3xy-y
=3(x-y)+5xy/(x-y)-3xy
=3*(-5xy)+5xy/-5xy-3xy
=-10xy/-8xy
=5/4本题根据分式的性质，我一开始也不会，前几天学完分式会了