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Rip-Off Rentals charges $25 per day plus 50¢ per mile to rent a mid-sized car. Your teacher will rent you his or her family sedan and charge you only 3¢ if you drive one mile, 6¢ if you drive two miles, 12¢ if you drive three, 24¢ for four, and so on. Homework Help ✎

  1. Write an equation that will give you the cost to rent each car.

  2. If you plan to rent the car for a two-day road trip, which is the better deal if you drive 10 miles? 20 miles? 100 miles?

Let d = number of days, m = number of miles, and y = total cost.

Your teacher is using a geometric sequence.

y = 25d + 0.5m and
y = 0.03(2)m−1

Substitute the values into each equation to see which rental costs less for each distance.