How do you condense #20lna-4lnb#?
So now we have
Now, using the rule
If you like, you can write this as
You can plug numbers in to these rules to make sure they work. For example,
More generally, we can show this rule and the others to be true. I will show that
Exponentiate both sides to get
Through rules of exponents, the right side can be rewritten to get
To finish, take the natural log of both sides to get
Similar things can be done to prove the other rules true.