CPM Homework Help : PC Problem 3-73

In the Math Note titled Definition of Logarithms, $b$ is restricted to positive values. Explain why.

Hint:

If $\log_{\left(−2\right)}\left(x\right)=1$ , what is the value of $x$ ?
If $\log_{\left(−2\right)}\left(x\right)=2$ , what is the value of $x$ ?