Is that (n+9)/(25n+9)? If thats the case the best way to do these problems is to look at the highest exponent of the numerator and the denominator. If they are the same the answer is a constant. If the numerator is higher it approaches infinity, and if the denominator is higher it approaches 0. Since the exponents are the same take n/25n to get 1/25. This is the answer. Hope this helps.