To multiply the expression \( (5x - 15) \) by \( \frac{1}{5} \), you can distribute \( \frac{1}{5} \) to each term in the parentheses:
\[ \frac{1}{5} (5x - 15) = \frac{1}{5} \cdot 5x - \frac{1}{5} \cdot 15 \]
Now simplifying each term:
- \( \frac{1}{5} \cdot 5x = x \)
- \( \frac{1}{5} \cdot 15 = 3 \)
So, combining these results, we get:
\[ x - 3 \]
Thus, the result of multiplying \( (5x - 15) \) by \( \frac{1}{5} \) is:
\[ x - 3 \]