已知1/x-1/y=5,则2x+3xy-2y/y+2xy-x

2个回答

  • 若是这样,则方法如下:

    由1/x-1/y=5,得:x、y都不为0.

    ∴(2x+3xy-2y)/(y+2xy-x)的分子和分母同除以(xy),得:

    (2x+3xy-2y)/(y+2xy-x)

    =(2/y+3-2/x)/(1/x+2-1/y)

    =[3-2(1/x-1/y)]/[2+(1/x-1/y)]

    =(3-2×5)/(2+5)

    =-1

    注:若原题不是我所猜测的那样,则请你补充说明.