Sally is comparing the prices of two window cleaning companies. company a charges $7 per window and ajbadditional $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 . part b: how much would company a and company b each charge for cleaning 8 windows ? very quick