Evan is deciding between two truck rental companies. Company A charges an initial
fee of $50 for the rental plus $0.50 per mile driven. Company B charges an initial fee
of $10 for the rental plus $1.50 per mile driven. Let A represent the amount
Company A would charge if Evan drives a miles, and let B represent the amount
Company B would charge if Evan drives a miles. Graph each function and determine
the interval of miles driven, z, for which Company A is cheaper than Company B.