A trampoline park costs $12 for the first hour and $6 for each additional hour. Flynn pays $30 at the trampoline park. Select the equation that represents the given situation and find the number of additional hours Flynn stays at the trampoline park after the first hour.
Let's say Flynn stays at the trampoline park for x additional hours after the first hour.
Therefore, the total cost for x additional hours is 6x dollars.
The equation that represents the given situation is 12 + 6x = 30.
To solve this equation, subtract 12 from both sides: 6x = 18.
Next, divide both sides by 6: x = 3.
Therefore, Flynn stays at the trampoline park for 3 additional hours after the first hour. Answer: \boxed{3}.