已知2x-y=10,求代数式[x²+y²-(x-y)²+2y(x-y)]÷4y的值
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已知2x-y=10,求代数式[x²+y²-(x-y)²+2y(x-y)]÷4y的值
已知2x-y=10,求代数式[x²+y²-(x-y)²+2y(x-y)]÷4y的值
已知2x-y=10,求代数式[x²+y²-(x-y)²+2y(x-y)]÷4y的值
[x²+y²-(x-y)²+2y(x-y)]÷4y
=[x²+y²-[x²-2xy+y²]+2xy-2y²)]÷4y
=[x²+y²-x²+2xy-y²+2xy-2y²]÷4y
=[4xy-2y²]÷4y
=x-y/2=1/2(2x-y)
再通过2x-y=10,有
原式=1/2(2x-y)=1/2×10=5