Two cars are traveling on two different routes. One is 43 miles longer. If the car traveling on the shorter route travels for 6 hours and it travels 2 mph slower than the other car, find the length of each route.
a. Shorter route: 86 miles, Longer route: 129 miles
b. Shorter route: 129 miles, Longer route: 172 miles
c. Shorter route: 172 miles, Longer route: 215 miles
d. Shorter route: 215 miles, Longer route: 258 miles