Solve the equation: 3x + 4 = 16. Show your work.

To solve the equation, we need to isolate x. 

Step 1: Subtract 4 from both sides of the equation.
3x + 4 - 4 = 16 - 4
3x = 12

Step 2: Divide both sides by 3.
(3x)/3 = 12/3
x = 4

So, the solution is x = 4.