已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]÷2y_数学解答

已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]÷2y

人气：171 ℃　时间：2020-02-01 06:05:38

解答

=[x^2+y^2-(x^2-2xy+y^2)+2xy-2y^2]÷2y
=[2xy+2xy-2y^2]÷2y
=[4xy-2y^2]÷2y
=2x-y
=10