Answer:
They sold 111 Hamburgers
Explanation:
Turn this into an equation: first, take the amount of hamburgers and call it 3x due to it being 3 times more than the amount of cheeseburgers, which we will can call x.
So, X+3X=444 is what you need to solve this. This is the same as 4x=444
So, x=111
Now, Input 111 for the final answer; 333 cheeseburgers and 111 hamburgers