Hamburgers = h
Cheeseburgers = c
c = h + 54
h = h
The word problem states there was a total of 804 burgers sold, so this means we have to set up an algebra equation. See example below:

Now let's plug in the value of c:

Combine like terms:

Isolate variable h:


Once again, isolate h:

h = 375.
Check your work and plug in values:

There were 750 hamburgers sold.