The cost of renting a medium-sized truck at U-Haul Rental is $30 per day plus $0.79 a mile. The cost of renting a similar truck at Discount Rentals is $24 per day plus $0.85 a mile. 

(a) Write a system of equations, with one equation representing the total cost of renting a truck from U-Haul for a day and the other equation representing the total cost of renting a truck from Discount Rentals for a day.

(b) Graph both equations for up to and including 200 miles on the same axes.

(c) Use the graph to estimate the number of miles that would need to be driven in a day for the cost of renting a truck from U-Haul to equal the cost of renting a truck from Discount Rentals.

Part of the question involves determining a system of equations that models the situation.