I am using numbers this time so you can convince yourself that the log law works.
LHS
= log (20/5)
= log 4
= 0.60206 (using calculator)
Now
RHS
= log 20 − log 5
= 1.30103 − 0.69897 (using calculator)
= 0.60206
= LHS
We have shown that the second logaritm law above works for our number example.