Answer:
(2,2)
Step-by-step explanation:
(5+-1/2,8+-4/2)
(-2,2)
3,6,8,5, these are your answers
The equation you can use is x + 3x = 428 with x as the number of cheeseburgers and 3x the number of hamburgers
you solve for x and get 4x= 428 and x=107
so 321 hamburgers were sold that day.