Question

Aaron deposited $400 in a saving account earning 3% simple interest. write an equation to represent how much money (y) Aaron would have after (x) years. use your equation to determine how much money Aaron would have in the account after 15 years.

Answer 1

$~~~~~~ \textit{Simple Interest Earned Amount \underline{in 15 years}} \\\\ A=P(1+rt)\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill & \ 400\\ r=rate\to 3\%\to \frac{3}{100}\dotfill &0.03\\ t=years\dotfill &15 \end{cases} \\\\\\ A=400[1+(0.03)(15)]\implies A=400(1.45)\implies A=580 \\\\[-0.35em] ~\dotfill\\\\ ~\hfill y=400(1.03x)~\hfill$