Find the values of A and B in the sum of fractions

If  $\dfrac{1}{3}$ = $\dfrac{1}{A}$ + $\dfrac{1}{B}$ where A and B are different whole numbers.Find the values of A and B.


MetroEye: As per Fractions01

$\dfrac{1}{3}$ = $\dfrac{1}{3+1}$ + $\dfrac{1}{3*(3+1)}$

$\dfrac{1}{3}$ = $\dfrac{1}{4}$ + $\dfrac{1}{12}$  

So A = 4 and B=12