Ask your own question, for FREE!
Mathematics 19 Online
OpenStudy (anonymous):

You drive 200 miles to city at an average speed 10 miles per hour faster than your usual average speed. If you completed the trip in 1 hour less than usual. What is your usual driving speed, in miles per hour?

OpenStudy (anonymous):

d=(r)(t)

OpenStudy (anonymous):

please help!!!

OpenStudy (anonymous):

d=rt 200=(s+10)(t-1)

OpenStudy (anonymous):

d=rt 200=rt

OpenStudy (anonymous):

200= rt-r+10t-10 200=200-r+10t-10 200=190-r+10t

OpenStudy (anonymous):

200-190=-r+10t 10=-r+10t

OpenStudy (anonymous):

r=10t-10

OpenStudy (anonymous):

200= (r+10)(t-1) 200=(10t-10+10)(t-1) we have substituted r

OpenStudy (anonymous):

200=(10t)(t-1) 200=10t^2-10t 0=10t^2-10t-200 which we can factorise

OpenStudy (anonymous):

0=10(t^2-t-20) 0=t^2-t-20 0=(t-5)(t+4) t=5 t=-4

OpenStudy (anonymous):

since time cannot be negative we take 5hrs

OpenStudy (anonymous):

now we find the speed =distance/time =200/5= 40mil/hr

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Latest Questions
kaelynw: starting to draw a hand
1 day ago 16 Replies 2 Medals
Twaylor: Rate it :D (Took 2 days)
2 days ago 7 Replies 0 Medals
XShawtyX: Art, Short Writing Assignment: Imagining Landscapes
1 hour ago 6 Replies 1 Medal
XShawtyX: Chemistry, Help ud83dude4fud83cudffe
2 days ago 13 Replies 1 Medal
kaelynw: tried a lil smt, the arm is off but i like the other stuff
3 days ago 27 Replies 3 Medals
kaelynw: art igg
3 days ago 14 Replies 1 Medal
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!