1 - 2 = 1 3 - 4 = 1 5 - 9 = 4 9 - 9 = 0 7 - 14 = 7 21 - 0 = 21 8 - 12 = 5 4 - 85 = 81 x is 8 and z is 5. x - z = 3 d is 2 and 8 is w and 17 is y. d - w - y = 7
Carlos would need to buy 4 cartons because a liter is 1000 ml. He needs 2000 ml/500 = 4
To multiply two fractions, you simply multiply numerators and denominators together.
2 can be read as the fraction 2/1
So, the multiplication is

1) 12 ounces of water to one packet of flavoring
2) 5 = 60, 7 = 84, 10 = 120, 12 = 144
4) 23 x 12 = 276 ounces of water