Christopher is deciding between two truck rental companies. Company A charges an
initial fee of $90 for the rental plus $1 per mile driven. Company B charges an initial
fee of $60 for the rental plus $2.50 per mile driven. Let A represent the amount
Company A would charge if Christopher drives a miles, and let B represent the
amount Company B would charge if Christopher drives a miles. Write an equation
for each situation, in terms of x, and determine the interval of miles driven, x, for
which Company A is cheaper than Company B.