Final answer:
To find the number of hamburgers sold on Sunday, we can set up a system of equations and solve for 'h'. The number of hamburgers sold on Sunday was 225.
Step-by-step explanation:
To find the number of hamburgers sold on Sunday, we can set up a system of equations based on the given information. Let's let 'h' represent the number of hamburgers sold and 'c' represent the number of cheeseburgers sold. We know that there were 399 hamburgers and cheeseburgers sold in total, so we can write the equation:
h + c = 399
We also know that there were 51 fewer cheeseburgers sold than hamburgers, so we can write the equation:
c = h - 51
Now we can solve this system of equations for 'h'. We can substitute the value of 'c' from the second equation into the first equation:
h + (h - 51) = 399
Simplifying the equation, we get:
2h - 51 = 399
Adding 51 to both sides of the equation, we get:
2h = 450
Dividing both sides of the equation by 2, we get:
h = 225
Therefore, 225 hamburgers were sold on Sunday.