Answer:
Let h be the number of hamburgers sold on Friday.
We know that the number of cheeseburgers sold was three times the number of hamburgers sold.
c = 3h
where c is the number of cheeseburgers sold.
We also know that the combined total of hamburgers and cheeseburgers sold was 584, so we can write:
h + c = 584
Substituting c = 3h into the second equation, we get:
h + 3h = 584
Simplifying:
4h = 584
Dividing both sides by 4, we get:
h = 146
Therefore, 146 hamburgers were sold on Friday.