Acar rental costs $50 for the first day. additional days cost $35 per day, unless the car is rented for 7 days or more, in which case there is a 10% discount on the daily rate. identify the expression which represents the cost of renting a car if the car has been rented for more than a week. a) 45 + 35x b) 45 + 31.5x eliminate c) 50 + 35x d) 50 + 31.5x