a plane traveled 285 miles to Perth and back. The trip there was with the wind. It took 3 hours. The trip back was into the wind. The trip back took 5 hours. What is the speed of the plane in still air? What is the speed of the wind?

Question

anonymous · Answer

x = speed of the plane
y = speed of the wind
one way trip is 285/2 = 142.5 miles

d = rt
d = (x + y)3        (the wind helps you out so you add x and y)
d = (x - y)5         (the wind hurts you so you subtract x and y) 

142.5 = 3x + 3y 
142.5 = 5x - 5y

Solve

Multiply top by -5  and bottom by 3  so the y's cancel

-5(142.5 = 3x + 3y)
3(142.5 = 5x - 5y)

do you know how to solve from here?

anonymous · Answer

yeah. thanks :)