To find an equivalent expression for \( \frac{1}{8^5} \), we can rewrite it using the properties of exponents.
- The expression \( \frac{1}{8^5} \) can be rewritten using negative exponents: \[ \frac{1}{8^5} = 8^{-5} \]
Now let's analyze the responses:
- \( 5^{-8} \) - This is not equivalent to \( \frac{1}{8^5} \).
- \( 8^5 \) - This is just \( 8^5 \), not equivalent either.
- \( 8^{15} \) - This does not match either.
- \( 8^{-5} \) - This is equivalent to \( \frac{1}{8^5} \).
So the correct response, if it were provided (which seems like it might be a formatting issue), would be \( 8^{-5} \).
If you must choose from the given options and considering \( 5^{-8} \), \( 8^5 \), and \( 815 \) do not correspond to \( \frac{1}{8^5} \), then none of the answers listed directly reflect \( \frac{1}{8^5} \).
Please check to see if the option representing \( 8^{-5} \) might be incorrectly represented or missing, as this is the only equivalent form to the expression given.