9. The value of U.S. postage stamps increases -5% per year. The current price is 55€. Estimate what the price will be in 20 years​

Respuesta :

[tex]\qquad \textit{Amount for Exponential Growth} \\\\ A=P(1 + r)^t\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{initial amount}\dotfill &\$0.55\\ r=rate\to 5\%\to \frac{5}{100}\dotfill &0.05\\ t=years\dotfill &20\\ \end{cases} \\\\\\ A=0.55(1 + 0.05)^{20}\implies A=0.55(1.05)^{20}\implies A\approx 1.46[/tex]