\begin{frame}
  \frametitle{Logarithmic Functions}

  We have the following cancellation equations:
  \begin{block}{}
  \begin{malign}
    \log_a (a^x) &= x \quad\text{for every $x \in \mathbb{R}$}\\[.5ex]
    a^{\log_a x} &= x \quad\text{for every $x > 0$}
  \end{malign} 
  \end{block}
  \pause\bigskip
  
  \begin{exampleblock}{}
    \begin{talign}
      \log_{10} (10^{23}) = 23
    \end{talign}
  \end{exampleblock}
  \pause\bigskip
  
  \begin{exampleblock}{}
    \begin{talign}
      5^{log_5 7} = 7
    \end{talign}
  \end{exampleblock}
\end{frame}