请写出我认识的过程，我初二thank you:>

(1/x为x分之一,以此类推,*为乘号)
因为(1/x)-(1/y)=5
所以(y-x)/xy=5..........................通分
所以y-x=5xy.............................两边同时乘xy
所以x-y=-5xy
所求分式(3x+5xy-3y)/(x-3xy-y)=[3(x-y)+5xy]/[(x-y)-3xy]....添括号
当y-x=5xy时
原式=[3(x-y)+5xy]/[(x-y)-3xy]
=(3*-5xy+5xy)/(-5xy-3xy).........................带入
=-10xy/-8xy......................................合并
=5/4............................................约分
完毕,谢谢

1/x-1/y=(y-x)/xy=5
y-x=5xy
3x-3y=-15xy
x-y-3xy=-8xy
原式=10xy/8xy=10/8=5/4

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

(3x+5xy-3y)/ (x-3xy-y)
=(-15xy+5xy)/ (-5xy-3xy)
=5/4

x分之—减y分之一=5 通分 （y-x）/(xy)=5 x-y=-5xy

所求=[3（x-y）+5xy]/[（x-y）-3xy]
=(-15xy+5xy)/(-5xy-3xy)=5/4

答案：4分之5
x分之1减去y分之1=5
变形 y-x=5xy则x-y=-5xy
所以 分母是x-3xy-y=x-y+（-3xy）=-8xy
分子是3x+5xy-3y=3（x-y）+5xy=-10xy

首先由1/X-1/Y=5,将左边通分可以得到(Y-X)/XY=5,得到Y-X=5