Question

如果2x-y=10,求代数式[(x²+y²)-(x-y)²+2y(x-y)]÷4y的值

Answer 1

如果2x-y=10

那么[(x²+y²)-(x-y)²+2y(x-y)]÷4y

=[(x²+y²)-(x²-2xy+y²)+(2xy-2y²)]÷4y

=(4xy-2y²)÷4y

=(2x-y)/2

=10/2

=5

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