Well any number you add can be irrational need more information.
Answer:
x=14
Step-by-step explanation:
you should set up your problem like this:
5x=3x+28
use order of operations aka PEMDAS to solve
you're answer is 14
Hey I can help give me one moment .
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.