## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$1.796$
Change of Base Formula: $\hspace{20pt} \log_ a M = \dfrac{\log_b M}{\log_b a}$ $\log_5 18 = \dfrac{\log_{10} 18}{\log_{10} 5}$ Where: $a=5 \hspace{10pt} M = 18 \hspace{10pt} b = 10$ $\dfrac{\log_{10} 18}{\log_{10} 5} \approx \boxed{1.796}$