9 of Estion Brooke Motors is a small car dealership. On average, it sells a car for $13,500 which it purchases from the manufacturer for $11,500. salespeople are paid a commission of $400 for each car they sell, the company pays a rent equal 10% of total revenues earned during each month. required 1-contribution margin per car 2- calculate breakeven point in units 3-explain your result in requirement 2 4 B