# How do you use the Change of Base Formula and a calculator to evaluate log_7 593?

Jun 9, 2015

The change of base formula allows you to calculate logs using a specified base usually 10 as this is all most calculators are able to evaluate.

#### Explanation:

${\log}_{a} \left(x\right) = \frac{{\log}_{10} \left(x\right)}{{\log}_{10} \left(a\right)}$

Therefore

${\log}_{a} \left(x\right) = \frac{{\log}_{10} \left(593\right)}{{\log}_{10} \left(7\right)}$

This is able to be evaluated on a calculator