已知2x^2-3xy-2y^2=0,则x+y/x-y=?

已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方 已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)} 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? 已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y) 已知x,y>0 2x+y+3=xy 求5x+4y最小值 已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值 已知x-y=4xy，则2x+3xy-2yx-2xy-y 已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y= 已知y-x-2xy=0,求3x+xy-3y/y-xy-x的值 已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 已知x^2-3y^2=2xy(x>0,y>0),求代数式x+2y/x-y