化简求值:已知2x-y=10求[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y的值_数学解答

化简求值:已知2x-y=10求[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y的值

人气：261 ℃　时间：2019-09-27 16:13:27

解答

[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y
=(x^2+y^2-x^2+2xy-y^2+2xy-2y^2)/4y
=(4xy-2y^2)/4y
=4x-2y=2(2x-y)=20
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