"A" is rather similar to "4" so I suppose there is a typo in between.
Here we go and obtain
We see from inspection that LHS of both equations (1) and (2) are equal. Therefore, RHS of both the equations must be equal.
Writing this in exponential form by definition of
Inserting the value of
LHS can be written using the rule for, addition of
Equating with RHS
Using the split the middle term method
We get two roots by putting each factor
The derivations for x = -4 and 1/2 are as in other two answers.
log of negative argument is unreal.