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,