x^2+xy-2y^2=0,则(x^3+3xy-2y^2)/(x^2-2y^2)

x²+xy-2y²=(x+2y)(x-y)=0所以x+2y=0,x-y=0所以x=-2y,x=yx=-2y则原式=(4y²-6y²-2y²)/(4y²-2y²)=-4y²/2y²=-2x=y则原式=(y²+3y²-2y²)/(y²-2y²)...