Maria is comparing the prices of two window cleaning companies. company a charges $6 per window and an additional $12 as service charges. company b charges $5 per window and an additional $15 as service charges. part a: write an equation to represent each company's total charges for cleaning a certain number of windows. for both equations (one for company a and one for company b), define the variable used. (4 points) part b: which company would charge less for cleaning 8 windows? justify your answer. (3 points) part c: how much money is saved by using the services of company b instead of company a to clean 6 windows? (3 points)