Answer:
I found:
141 hamburgers and 423 cheeseburgers
Step-by-step explanation: Call
h and c the number of the two items. You get:
{ H + C = 564.
{ C = 3h
substitute the second into the first:
H + 3h = 564
4h = 564
H = 564/4 = 141 hamburgers
use this back into the second equation:
c = 3 • 141 = 423 cheeseburgers.