Question

teach me basics about logarithms

Answer 1

Logarithm of a positive number x to the base a ( a is a positive number not equal to 1 ) is the power y to which the base a must be raised in order to produce the number x. 

logax =y because ay=x     a > 0 and a ≠ 1

Answer 2

Example:$log 3^{9}$
To find log for this firstly ask to yourself that "to what power is can 3 be raised to get 9 as the answer?"
Then you would get the answer as 2 because $3^{2}$=9
So the answer is 2.