Respuesta :
Answer:
65 mph on level road
Step-by-step explanation:
Set b as average speed on the level road and (b-20) = average speed on the winding road
Distance = speed * time
Level Road distance + winding road dististance = 285 miles
Substituting b and (b-20), we have,
3b + 2(b-20) = 285
3b + 2b - 40 = 285
5b = 285 + 40
5b = 325
b= 325/5
b = 65 mph on level road
Answer: 52 mph
Step-by-step explanation:
Assume the following :
a = average speed traveled on level road
(a - 20) = average speed traveled on winding road
Recall:
Distance = speed × time
Total distance traveled :
Level road distance + winding road distance = 252 miles
3a + 3(a - 20) = 252
3a + 3a - 60 = 252
6a = 252 + 60
6a = 312
a = 52 mph on a level triad