[tex]\bf \qquad \textit{Amount for Exponential Decay}\\\\
A=P(1 - r)^t\qquad
\begin{cases}
A=\textit{accumulated amount}\\
P=\textit{initial amount}\to &12500\\
r=rate\to 9\%\to \frac{9}{100}\to &0.09\\
t=\textit{elapsed time}\\
\end{cases}
\\\\\\
A=12500(1-0.09)^t\implies A=12500(0.91)^t
\\\\\\
\textit{after 5 years t = 5}\qquad A=12500(0.91)^5[/tex]
and surely you know how much that is.
