Answer
$\dfrac{1}{2}$
Work Step by Step
Recall:
$$\log_a{b}-\log_a{c}=\log_a{\left(\frac{b}{c}\right)}$$
Thus, the given expression is equivalent to:
$$=\log_9{\left(\frac{27}{9}\right)}=\log_9{3}=\log_9{\left(9^{\frac{1}{2}}\right)}$$
Recall:
$$\log_a{(a^n)}=n$$
Hence,
$$\log_9{\left(9^{\frac{1}{2}}\right)}=\frac{1}{2}$$
Therefore,
$$\log_9{27}-\log_9{9}=\frac{1}{2}$$
