To start off this problem, you must change each of the fractions to their least common denominator. Between 32 and 16, the number we shall use is 32. Therefore, nothing needs to be changed for the first fraction, but the second fraction needs to have a 32 at the bottom. So, you must multiply the denominator numerator by 2 (giving you the new, equivalent fraction of 2/32).
Now, all you have to do is subtract the fractions. Since the denominators are the same, all you have to do is 9 minus 2, which equals 7 over 32 (or 7/32) as your final answers. Typically, you would simplify the fraction after this, but in this case, it is not necessary due to the fact that it is in simplest form already. I hope this helps!