Answer:
Simplify the expression: 

The top expression given in the above fraction is Numerator and the bottom expression is called Denominator.
Now, multiply the numerator and denominator by 
 ;

Simplify:

Now, Factor the numerator 
 and denominator 
;

Now, cancel the common factor (b+3) we get;

Therefore, the simplify expression of 
 is, 
