Company A charges a one-time fee of $60, and $25 per hour. Company B charges a one-time fee of $120, and $20 per hour.
a) Write an equation representing the total cost of Company A, and an equation representing the total cost of company B.
b) After how many hours is the cost to use both companies equal?
c) You want to use one of the companies for 7 hours. Which is cheaper?