Evaluate:

$\displaystyle log_28^{27} - log_464^{\frac {1}{5}}$

My work:

$\displaystyle = log_2(2^{3})^{27} - log_4 \sqrt [5] {64}$

$\displaystyle = log_2 2^{81} - \frac {1}{5} log_464$

$\displaystyle = 81 log_22 - \frac {1}{5} log_44^{3}$

And now what do I do? I don't know how to put both in the same base