A=-1/(2+根号5)=2-根号5 1/A=-2-根号5
(9-6a+a^2)/(a-3)+根号(a^2-2a+1)/(a^2-a)
=(A-3)方/(A-3)+(1-A)/[A(A-1)]
=A-3-1/A
=2-根号5-3+2+根号5
=1