Thank you!
i believe you'd use logarithms
Working with Exponents and Logarithms
Method 1: Use a logarithm of base a.
$\displaystyle \displaystyle \begin{align*} a^b &= c \\ \log_a{\left( a^b \right)} &= \log_a{(c)} \\ b &= \log_a{(c)} \end{align*}$
Method 2: Use a logarithm of ANY base.
$\displaystyle \displaystyle \begin{align*} a^b &= c \\ \log_k{\left( a^b \right)} &= \log_k{\left( c \right)} \\ b \log_k{(a)} &= \log_k{(c)} \\ b &= \frac{\log_k{(c)}}{\log_k{(a)}} \end{align*}$