Answer
$x=\dfrac{1}{64}$
Work Step by Step
RECALL:
$\log_b{a}=y \longrightarrow b^y=a$
With $a=x$, $b=4$, and $y=-3$, use the rule above to the given expression to obtain:
$4^{-3}=x$
Use the rule $a^{-m} = \dfrac{1}{a^m}$ to obtain:
$\dfrac{1}{4^3} = x
\\\dfrac{1}{4(4)(4)}=x
\\\dfrac{1}{16(4)}=x
\\\dfrac{1}{64}=x$
