题目

先化简再求值:x²-1/x²-2x+1/x+1/x-1*1-x/1+x,其中x=1/2

提问时间：2020-12-16

答案

x²-1/x²-2x+1/x+1/x-1*1-x/1+xx²-1/x²-2x+1=(x+1)(x-1)/(x-1)^2=(x+1)(x-1)x²-1/x²-2x+1/x+1/x-1=(x²-1/x²-2x+1)(x-1)/(x+1)=(x+1)(x-1)(x-1)/(x+1)=(x-1)^2x²-1/x
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