[tex]~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill & \$1512\\ P=\textit{original amount deposited}\\ r=rate\to 3.5\%\to \frac{3.5}{100}\dotfill &0.035\\ t=years\dotfill &12 \end{cases} \\\\\\ 1512 = (P)(0.035)(12)\implies \cfrac{1512}{(0.035)(12)}=P\implies 3600=P~\hfill \boxed{\underset{\textit{total repay}}{\stackrel{3600+1512}{5112}}}[/tex]
