fast shuttle : 5 + 0.25m
steady shuttle : 2 + 0.50m
when will they be equal.....so set them equal and solve for m, the number of miles
5 + 0.25m = 2 + 0.50m
5 - 2 = 0.50m - 0.25m
3 = 0.25m
3 / 0.25 = m
12 = m <=== so they will cost the same at 12 miles