josh rode his bike 17mi from his home to Colombus, and then traveled 53mi by car from Colombus to Dayton. Assume that the average rate of the car was...

josh rode his bike 17mi from his home to Colombus, and then traveled 53mi by car from Colombus to Dayton. Assume that the average rate of the car was 43mph faster than the average rate of the bike.

a. express the total time required to complete the 70mi trip (bike and car) as a fuction of the rate x of the bike.

b. find graphically the rate of the bike if the total time of the trip was 1hr 40min. Confirm algebraically.