[tex]~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill&\$790\\ P=\textit{original amount deposited}\\ r=rate\to 4\%\to \frac{4}{100}\dotfill &0.04\\ t=years\dotfill &5 \end{cases} \\\\\\ 790=P(0.04)(5)\implies \cfrac{790}{(0.04)(5)}=P\implies \boxed{3950=P}[/tex]
