x²-1=0,
(x+1)(x-1)=0
x1=-1 x2=1
x-1/x÷(x-{2x-1/x})
=（x-1）/x÷(x²-2x+1）/x
=（x-1）÷（x-1）²
=1/(x-1) (x只能x=-1)
=1/(-1-1)
=-1/2
如追加其它问题,采纳本题后点击想我求助,