# How do you solve #ln x - ln 4 = 7#?

##### 1 Answer

Oct 28, 2015

You must see the explanation!

#### Explanation:

You need to know that :

log to base 10 of

log to base

log to base

Addition of loges reflects multiplication of the source numbers.

Subtraction of logs reflects division of the source numbers.

This is so because you are dealing with indices (powers).

This is stating that:

so

so