先将代数式(x-x+1/x)÷(1+x²-1/1)化简,再在-1,0,1,2中选取一个合适的数X带入求值
问题描述：
先将代数式(x-x+1/x)÷(1+x²-1/1)化简,再在-1,0,1,2中选取一个合适的数X带入求值
答
(x-x+1/x)÷(1+x²-1/1)=[(x+1)/(x²+x-x)]÷[(x²-1)/(x²-1+1)]=[(x+1)/(x²)]÷[(x²-1)/(x²)]=[(x+1)/(x²)]*[(x²)/(x-1)(x+1)]=x-1当x=2时上式=1