已知2x平方-xy-3y平方=0,且x不等于-y,求x比上y-（x-y）分之x平方

2x²-xy-3y²=0(x+y)(2x-3y)=0x=-y(舍去)或x=3y/2x/y=3/2x/y-x²/(x-y)=x/y-x²/(x²-2xy+y²)=x/y-(x/y)²/[(x/y)²-2(x/y)+1]=(3/2)-(3/2)²/[(3/2)²-2(3/2)+1]=-15/2