SOLUTION: An airplane flies 1449 mi against the wind
and 1539 mi with the wind in a total time of 5 hr. The
speed of the airplane in still air is 600 mph. What is the speed of the wind?
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-> SOLUTION: An airplane flies 1449 mi against the wind
and 1539 mi with the wind in a total time of 5 hr. The
speed of the airplane in still air is 600 mph. What is the speed of the wind?
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Question 876953: An airplane flies 1449 mi against the wind
and 1539 mi with the wind in a total time of 5 hr. The
speed of the airplane in still air is 600 mph. What is the speed of the wind? Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = the windspeed in mi/hr = the speed of the plane
flying with the wind = the speed if the wind
flying against the wind
------------------------
(1)
(2)
(3)
----------------------------
There are 3 equations and 3 unknowns
so it's solvable
(1)
(2)
------------------------------
By substitution:
(3)
Multiply both sides by
(3)
(3)
(3)
(3)
(3)
-----------------------------
I'll try completing the square:
(3)
(3)
(3)
(3)
Take the square root of both sides
(3)
(3)
The windspeed is 48 mi/hr
-------------------------
check:
(1)
(1)
(1)
and
(2)
(2)
(2)
and
(3)
(3)
(3)
OK
