Question

Taber invested money in an account where interest is compounded every year. He made no withdrawals or deposits. The function A(t) = 525(1 + 0.05)^t represents the amount of money in the account after t years. How much money did Taber originally invest?

Answer 1

$\bf ~~~~~~ \textit{Compound Interest Earned Amount}\\\\A=P\left(1+\frac{r}{n}\right)^{nt}\quad \begin{cases}A=\textit{accumulated amount}\\P=\textit{original amount deposited}\to &\ 525\\r=rate\to 5\%\to \frac{5}{100}\to &0.05\\n=\begin{array}{llll}\textit{times it compounds per year}\\\textit{every year, thus once}\end{array}\to &1\\t=years\to &t\end{cases}\\\\\\A=525\left(1+\frac{0.05}{1}\right)^{1\cdot t}\implies A(t)=\stackrel{\downarrow }{525}(1+0.05)^t$

Answer 2

So that would be 525 $ € or whatever currency he used :)