Math Help - Logarithm help

1. Logarithm help

I don't understand how you can get -2 out of log base 2 1/4 ?

2. $\log_2 \frac{1}{4} = \log_2 \frac{1}{2^2} = \log_2 2^{-2}= -2 \times \log_2 2 = -2 \times 1$

3. Here's another way:

$\log_2 \frac{1}{4}=x$ is equivalent to $2^x=\frac{1}{4}=2^{-2}$.

So $x=-2$.