Okay, here we have this:
We need to solve the following equation for n:
[tex]\log _8n=3[/tex]To solve this equation we will pass the logarithm to its exponential form:
[tex]\begin{gathered} n=8^3 \\ n=8\cdot8\cdot8 \\ n=512 \end{gathered}[/tex]Finally we obtain that n=512.