You may want to review logarithms first.

You can solve equations involving logarithms. But you have to be
careful to read them carefully, to see where the *x* is! If
the equation is log_{1 ⁄ 2}
(1 ⁄ 2) = *x*, say, then it's just asking
you to compute log_{1 ⁄ 2}
(1 ⁄ 2), just as in the last section; the
answer is *x* = 1. If you're asked to solve log_{x}
(3 ⁄ 11) = 1, that means that *x*^{1}
= 3 ⁄ 11. The answer is then
*x* = 3 ⁄ 11. Finally, if you're asked to
solve log_{16} *x* = 2, that means that
16^{2} = *x*; so now the answer is 256.