已知x+2y=0,求分式2xy+y^2/x^2-xy
已知x+2y=0,求分式2xy+y^2/x^2-xy
已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值.
已知2x-3y=0,求分式x^2+xy-y^2/2x^2+xy-y^2
已知x+2y=0(x不等于0)求分式2xy+y^2/x^2-xy
已知1/x-1/y=3,求分式(2x+3xy-2y)/(x-2xy-y)
已知1/x-1/y=5 求分式-x+xy+y/2x+7xy-2y
已知1/x-1/y=5,求分式y+xy-x/2x+7xy-2y的值.
已知1/X-1/y=5,求分式(y+xy-x)/(2x+7xy-2y)的值
已知1/x+1/y=3,求分式3x-2xy+3y/x+xy+y的值
已知,1/x+1/y=5.,求分式3x+xy+3y/x-2xy+y的值
已知x+2y=0,xy不=0,求分式(x^2+2xy-y^2)/(2x^2+xy+y^2)的值
已知x-3y=0,且xy不等于0,求分式x*2-xy+y*2/x*2+xy+y*2的值