Question

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

Answer 1

[(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