已知x=3y,求2x+y/x05-2xy+y05× - 知识问答

已知x=3y,求2x+y/x05-2xy+y05×(x-y)的值

3个回答

[(2x+y)/(x²-2xy+y²)]·(x-y)
=[(2x+y)/(x-y)²]·(x-y)
代入x=3y
原式=(7y/4y²)·2y
=(7/4y)·2y
= 7/2

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