(a^2-2a+1)/(a-1)-(a-2)=(a-1)^2/(a-1)-(a-2)=(a-1)-(a-2)=a-1-a+2=2-1=1
(a^2-2a+1)/(a-1)-(a-2)=(a-1)^2/(a-1)-(a-2)=(a-1)-(a-2)=a-1-a+2=1
