已知2x-y=2014,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y

[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y=(x^2+y^2-x^2-y^2+2xy+2yx-2y^2)/4y=(4xy-2y^2)/4y=(2xy-y^2)/2y=[y(2x-y)]/2y=(2x-y)/2=2014/2=1007