Since he only spends 3 dollars on kids meals, we can subtract that from 28 to get 28-3-25. Next, we have to find out how much he paid for 5 sandwiches given that he has 25 dollars. If the cost of each sandwich is x, we therefore add x dollars for each sandwich purchase and we're left with 5x=25. Dividing both sides by 5, we get x=5
