如果2x-y=8,求代数式[(x^2+y^2)-(x-y)^2+2y(x-y)]除以(4y)的值.

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如果2x-y=8,求代数式[(x^2+y^2)-(x-y)^2+2y(x-y)]除以(4y)的值.

如果2x-y=8,求代数式[(x^2+y^2)-(x-y)^2+2y(x-y)]除以(4y)的值.
如果2x-y=8,求代数式[(x^2+y^2)-(x-y)^2+2y(x-y)]除以(4y)的值.

如果2x-y=8,求代数式[(x^2+y^2)-(x-y)^2+2y(x-y)]除以(4y)的值.
((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)
=(2x-y)/2=8/2=4

原式=[x^2+y^2-x^2+2xy-y^2+2xy-2y^2]/4y
=y[4x-2y]/4y
=[2x-y]/2
=4


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