If you would like to find the rate of the bicycle and the scooter, you can do this using the following steps:
a scooter: 18 miles ... 2 * r + 5 mph
a bicycle: 8 miles ... r = ?
18 * r = 8 * (2 * r + 5)
18 * r = 16 * r + 40
18 * r - 16 * r = 40
2 * r = 40
r = 20 mph
a bicycle: r = 20 mph
a scooter: 2 * r + 5 mph = 2 * 20 + 5 = 45 mph
The correct result would be: The rate of the scooter is 45 mph and the rate of the bicycle is 20 mph.
