x^2-2x+1/x^2-1+x-1/x^2+x- - 知识问答

x^2-2x+1/x^2-1+x-1/x^2+x-x的值,其中x=2007,某同学把x=2007错抄成x=2008,但它

1个回答

原式=(x-1)^2/(x+1)(x-1)+(x-1)/x(x+1)-x
=(x-1)/(x+1)+(x-1)/x(x+1)-x
=(x^2-x+x-1)/(x+1)-x
=(x+1)(x-1)/(x+1)-x
=x-1-x
=-1
所以不论x取何值,结果都是-1

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