The monthly revenue of a digital magazine from each user is represented by f(x) = 2x+15. the monthly cost to provide the digital magazine to each user per month is represented by g(x) = x2. which of the following evaluates the profit function for each user of the digital magazine after 3 months? (f – g)(3) = (2(3) + 15) – 32 = 21 – 9 = $12 (g – f)(3) = 32 – (2(3) + 15) = 9 – 21 = −$12 (f + g)(3) = (2(3) + 15) + 32 = 21 + 9 = $30 (g – f)(3) = 32 – 2(3) + 15 = 9 – 6 + 15 = $18