Answer :

(3 * n) +4 = 16
(3 * n) = 12
n = 4
Incase that wasn't clear^.

32/2 = 16
So (3*N) + 4= 16
Subtract 4 from both sides
(3*N)=12
Divide both sides by 3.
N=12/3
12/3=4
N=4