48 of the pizzas would be cheese because you divide 80 by 5 and get 16 then multiply that by 3 to get 48
Starting from what I know (the difference between ribbons), I decided to go from the bottom and work my way up. I then noticed a pattern (each sum was three more of the previous one), and decided to keep my pattern of the three numbers but not have to do any major mental work and instead add three to the previous sum until I got to 38.
The first one is 11 and -11 because when you square them they both get 121
The second one is -7 and -1