Answer
$1$
Work Step by Step
We know that $\log_a {x}-\log_a {y}=\log_a {\left(\frac{x}{y}\right)}$.
Hence,
$\log_6 {18}-\log_6 {3}
\\=\log_6{\left(\frac{18}{3}\right)}
\\=\log_6 {6}
\\=\log_6 {6^1}$.
We know that $\log_a {a^x}=x$.
Thus, $\log_6 {6^1}=1$
