Mabel is comparing the prices of two car rental companies. company a charges $35 per day and an additional $15 as service charges. company b charges $42 per day and an additional $10 as service charges. part a: write an equation to represent each company's total charges for renting a car for a certain number of days. for both equations (one for company a and one for company b., define the variable used. part b: which company would charge less for renting a car for 6 days? justify your answer. part c: how much money is saved by using the services of company a instead of company b to rent a car for 10 days?