Question

The average speed of an express train is 15mi/hr faster than the average speed of a local train. It takes the local train 2 hours longer than the express train to cover 360 miles. What is the average speed of the express train?

Answer 1

speed = dist / time
let the local train speed be x
x = 360 / 2 + t
x + 15 = 360 / t
360/t - 15 = 360 / 2 + t
360 - 15t / t = 360 / 2 + t
(t+2) ( 360 - 15t) = 360t
-15t^2 - 30t + 720 = 0
t^2 + 2t - 48 = 0
t^2 + 8t -6t -48=0
t(t+8)-6(t+8) = 0
t = 6 or -8
t = 6
x+15 = 360/6 = 60
x = 60 - 15 = 45 miles / hr

Answer 2

the answer says 60 mi/hr acutally...

Answer 3

45 miles / hr is the slower train
the express is therefore 60 miles / hr

Answer 4

oh icic

Answer 5

i had this exact problem in my homework. you using the holt alg 1 book?

Answer 6

yhea.... where do u live?

Answer 7

california

Answer 8

well durrrr only california uses the california standards

Answer 9

irvine

Answer 10

omg me too o.O

Answer 11

slms?

Answer 12

lisa?

Answer 13

:O

Answer 14

hi :D

Answer 15

LOL hi

Answer 16

LOL WHO ARE YOUUUUU

Answer 17

anthony.... lol, who else did you give this website to?

Answer 18

AHAHAHAHAHAHHAHA

Answer 19

HI ANTHONY XDDDDD LOLOLOLOL

Answer 20

HI LISA xD
mr. orchestra?

Answer 21

no i thought it was you, but ur username is like non anthony ish xD you can tell, mine is lisa ish :D

Answer 22

yeah... i thought it was you when i read the problem lol
i use that username for most websites

Answer 23

dude i dont get ANY of the math hw TT.TT so as you can see, im posting like everysinge one haha

Answer 24

o icic xD

Answer 25

yeah... i noticed
i'm not doing my math hw until sunday lol

Answer 26

well i gtg now cya on monday xD LOL u made my night hahahaha

Answer 27

hahahaha i wonder what the other person that replied to this post will think XD

Answer 28

XD