Chapter 5 - Exponential and Logarithmic Functions - 5.5 Properties of Logarithms - 5.5 Assess Your Understanding - Page 305: 28

$3$

We know that $\log_a {x^n}=n\cdot \log_a {x}$. Hence, $e^{\log_{e^2}{9}} \\=e^{\log_{e^2}{3^2}} \\=e^{2\log_{e^2}{3}}$. We also know that $a^{\log_a {x}}=x$. Thus, $e^{2\log_{e^2}{3}} \\=(e^2)^{\log_{e^2}{3}} \\=3$