SOLUTION: Two planes left an airport at noon. One flew east at a certain speed and the other flew west at twice the speed. The plains were 2700 miles apart in 3 hours. How fast was each plan

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Question 154399This question is from textbook
: Two planes left an airport at noon. One flew east at a certain speed and the other flew west at twice the speed. The plains were 2700 miles apart in 3 hours. How fast was each plane flying? This question is from textbook

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!
Remember:
Speed of the 2 planes in miles%2Fhour
Plane1=P%5B1%5D=+x%28mi%2Fhr%29
Plane2=P%5B2%5D=2x%28mi%2Fhr%29, twice the speed of P%5B1%5D
As they left the airport, the 2 plane made a combined distance of 2700miles in 3hours. So,
P%5B1%5D%2BP%5B2%5D=2700miles%2F3hours -------------------------> working eqn
x%2B2x=cross%282700%29900%2Fcross%283%29
3x=900%28mi%2Fhr%29
cross%283%29x%2Fcross%283%29=cross%28900%29300%2Fcross%283%29
x=300%28mi%2Fhr%29 ----------------------------> speed of P%5B1%5D
Also, P%5B2%5D=2%2A300=600%28mi%2Fhr%29, speed of P%5B2%5D
In doubt? Go back working eqn:
300%2B2%28300%29=2700%2F3
300%2B600=900
900%28mi%2Fhr%29=900%28mi%2Fhr%29
Thank you,
Jojo