How do you express #log_7 5# in terms of common logs?

1 Answer
Nov 20, 2016

#log5/log7#

Explanation:

A common log is a log to the base of 10. Logs to the base of 10 are usually simply written as #logx# rather than #log_10x#, so keep that in mind for my explanation.

The change of base formula states that #log_ab=logb/loga#.
Therefore, #log_7 5=log5/log7#.