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

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

已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
3/(x-y)=1/xy
x-y=3xy
y-z=-3xy
原式=[(y-x)-2xy]/[2(x-y)+3xy]
=[(-3xy)-2xy]/[2(3xy)+3xy]
=-5xy/9xy
=-5/9