先化简再求值:x²-1/x²-2x+1/x+1/x-1*1-x/1+x,其中x=1/2
问题描述：
先化简再求值:x²-1/x²-2x+1/x+1/x-1*1-x/1+x,其中x=1/2
答
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...