[(X平方+ Y平方)-(X-Y)的平方+2Y(X-Y)]÷4y的值,其中2x-y=8

学习时间:2026-09-28 16:38:33 阅读：9351

[(X平方+ Y平方)-(X-Y)的平方+2Y(X-Y)]÷4y的值,其中2x-y=8快急用啊

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2026-09-28 16:38:33

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答：[(X平方+ Y平方)-(X-Y)的平方+2Y(X-Y)]÷4y=[(x²+y²)-(x-y)²+2y(x-y)]/(4y)=(x²+y²-x²+2xy-y²+2xy-2y²)/(4y)=(4xy-2y²)/(4y)=(2x-y)/2=8/2=4