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