Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation;
3*n-4-(14)=0 
Pull out like factors :
   3n - 18  =   3 • (n - 6) 
Solve :    3   =  0
This equation has no solution.
A a non-zero constant never equals zero.
Solve  :    n-6 = 0 
 Add  6  to both sides of the equation : 
                      n = 6