Answer
(a) $2$
(b) $2$
(c) $10$
Work Step by Step
RECALL:
(1) $\log_b{b}=1$
(2) $\log_b{1}=0$
(3) $\log_b{b^x}=x$
(a) Write $36$ as $6^2$, then use rule (3) above to obtain:
$=\log_6{6^2}
\\=2$
(b) Write $81$ as $9^2$, then use rule (3) above to obtain:
$=\log_9{9^2}
\\=2$
(c) Use rule (3) above to obtain:
$=\log_7{7^{10}}
\\=10$
