#### Answer

$0$

#### Work Step by Step

RECALL:
$\log_b{x}=y \longrightarrow b^y=x$
Let
$\log_b{b} = y$
Use the rule above to obtain:
$\log_b{1}=y \longrightarrow b^y=1$
Note that $b^0=1$.
Replace $1$ with its equivalent $b^0$ to obtain:
$b^y=b^0$
Use the rule $a^m=a^n \longrightarrow m=n$ to obtain:
$b^y=b^0 \longrightarrow y = 0$
Thus, the missing expression in the given statement is: $0$