A soda vendor at Aloha Stadium noticed that during Rainbow Warrior football games that more soda is being served the warmer the temperature during game time. Based on 40 home games covering the past 5 years, the vendor estimates the relationship between soda sales and game time temperature to be y = -240 + 8x, where y = the number of sodas sold during the game and x = the temperature during game time in degrees Fahrenheit.