Answer
$3 - \log_4{y}$
Work Step by Step
RECALL:
The quotient rule for logarithms states:
$\log_a{\left(\frac{b}{c}\right)} = \log_a{b} - \log_a{c}$
Use the quotient rule to obtain:
$\log_4{\left(\frac{64}{y}\right)}
\\= \log_4{64} - \log_4{y}
\\=\log_4{(4^3)} - \log_4{y}$
Note that for all real numbers within its domain, $\log_a{(a^n)}=n$.
This means that $\log_4{(4^3)} =3$.
Thus,
$\log_4{(4^3)} - \log_4{y}= 3 - \log_4{y}$
