To subtract the fractions \( \frac{9}{5} - \frac{5}{5} \), we first observe that the denominators are the same (both are 5).
Now, we can subtract the numerators:
\[ \frac{9}{5} - \frac{5}{5} = \frac{9 - 5}{5} = \frac{4}{5} \]
So, the answer in simplest form is:
\[ \frac{4}{5} \]