In order to solve this problem we will say that Audrey's riding speed is equal to "x" mph. Since her hiking speed is 9 mph less than her riding speed, then it is "x -9" mph. The average speed formula is given by:
speed = distance/time
Thefore the time to travel a certain distance with a certain speed is:
time = distance/speed
Her time to hike 6 miles is the same as her time to ride 25 miles, therefore:
