Answer: A = 15 + 0.5(w)
Step-by-step explanation: The above equation represents the amount of dollars after selling w cups of water. Remember: we also have 15 in advance, so we add that to the total amount of cups sold. We multiply 0.5 (the amount earned per water cup) by w (the number of water cups sold) and we will get our answer.
To check this, let's say we sold 10 water cups. So w = 10. Therefore, we write A = 15 + 0.5(10). That = A = 15 + 5 which A = 20. We can use any number in place of w now and we will know it is correct using this formula