计算x²-x/x²×x/1-x和x²-4y²/x² - 知识问答

计算x²-x/x²×x/1-x和x²-4y²/x²+2xy+y&sup

1个回答

x²-x/x²×x/1-x
=x(x-1)/x²×x/[-(x-1)]
=-1
x²-4y²/x²+2xy+y²÷x+2y/x²+xy
=(x+2y)(x-2y)/(x+y)²×x(x+y)/(x+2y)
=x(x-2y)/(x+y)
=(x²-2xy)/(x+y)

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