A national park has two options: a $50 pass for all admissions during the year, or a $4 entrance fee each time you enter.

a. Model Write an equation to model the cost of going to the park for a year using a pass and another equation for paying a fee each time. 

b. Graph Graph both equations you wrote in part (a). 

c. Interpret How many visits do you need to make for the pass to be cheaper? Explain.