Answer
$-2$
Work Step by Step
Recall the power property of logarithms (pg. 462):
$\log_b{m^n}=n\log_b{m}$
We rewrite the values in the form of $m^n$, so that we can apply
the power property:
$\log_{2}{4}-\log_2{16}\\
=\log_{2}{2^2}-\log_2{2^4}\\
=2\log_{2}{2}-4\log_2{2}\\
=2\times1-4\times 1\\
=2-4\\
=-2$
We also used the fact that $\log_{2}{2}=1$ (because $2^1=2$).
