Question

How do you use the Change of Base Formula and a calculator to evaluate the logarithm `log_15 7`?

Answer 1

The change of base rule is: `log_an = (logn)/(loga)`

Explanation:

`log_7(15) = (log15)/(log7)`

Now that both logs are in base 10, you can evaluate using a regular scientific calculator by pressing the button labelled "log".

Answer: 1.39

Hopefully this helps!