Answer:
?
Step-by-step explanation:
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
(10c² +49cd+49d²) ÷ (5c+7d)
(5c+7d)(2c+7d) ÷ (5c+7d)
Delete (5c+7d)
= (2c+7d)