Thread: can anyone help me break down these calculations? (logarithms)

Hi i'm working on a question on logarithms.

I've attached the calculations as an image.

I can't seem to understand these calculations; in particular the second line. I am not able to understand where the second log (base 10) has come from.

Any help is hugely appreciated! thank you

If you take the base 10 log of both sides of the first equation you will have the second equation.