x的平方-2x+1分之x²-1+x-2分之2x-x²除以x
=（x+1）（x-1）/（x-1）²-x(x-2)/(x-2)÷x
=（x+1）/(x-1)-1
=(x+1-x+1)/(x-1)
=2/(x-1)
如果本题有什么不明白可以追问,