algebra
posted by franklin .
Company A charges $55 per day plus $0.35 per mile to rent a car. Company B charges $50 per day plus $0.40 per mile. Jack wants to rent a car for three days. How many miles should Jack be traveling so that Company A is less expensive than Company B?

A: cost= 3*55+.35m
B: cost=3*50+.40m
set the costs equal, and solve for m. 
so 12(8)x â‰¥ 72
x â‰¥ 72/96
x â‰¥ 3/4 ft