Question

Isabella borrowed money to start a business. at a rate of 4% simple interest. After 10 years, she has accumulated $800 in interest. How much did she initially borrow.

Answer 1

`~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill & \$800\\ P=\textit{original amount deposited}\\ r=rate\to 4\%\to (4)/(100)\dotfill &0.04\\ t=years\dotfill &10 \end{cases} \\\\\\ 800 = (P)(0.04)(10)\implies \cfrac{800}{(0.04)(10)}=P\implies 2000=P`