Question

Money is borrowed at 9​% simple interest. After one​ year, ​$1178.29 pays off the loan. How much was originally​ borrowed?

Answer 1

`\bf ~~~~~~ \textit{Simple Interest Earned Amount} \\\\ A=P(1+rt)\qquad \begin{cases} A=\textit{accumulated amount}\dotfill&1178.29\\ P=\textit{original amount deposited}\dotfill \\ r=rate\to 9\%\to (9)/(100)\dotfill &0.09\\ t=years\dotfill &1 \end{cases} \\\\\\ 1178.29=P(1+0.09\cdot 1)\implies 1178.29=P(1.09)\implies \cfrac{1178.29}{1.09}=P \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill 1081=P~\hfill`