For this case, we must find the equation of the line. The generic equation of the line is: The slope of the line is: Substituting values we have: Rewriting: We now choose an ordered pair: (xo, yo) = (0, 12) Substituting values we have: Rewriting the equation: For 20 visits, we evaluate the equation when x = 20. We have then: Answer: The discounted entrance fee is 1.5$. The total cost is 42$ after 20 visits