(x/2y)^2*y/2x-x/y^2/(2y^2/x) =x^2/4y^2*y/2x-x/y^2*(x/2y^2)=x/8y-x^2/2y^4(x/x+y+2y/x+y)*xy/x+2y/(1/x+1/y) =(x+2y)/(x+y)*xy/(x+2y)/[(x+y)/xy]=xy/(x+y)*xy/(x+y)=x^2y^2/(x+y)^2(1/a+1/b)^2/(1/a^2-1/b^2)=(1...