I need help with this problem....

[lyssa]

A plane took 2 hours to make a 600km trip when flying with the wind. The return trip, flying against the wind took 2.5 hours. Find the wind speed and the planes air speed.

I have tried to tackle it this way:
2.5x + y = 600 and 2x + y = 600

I have the answer sheet and I can't come anywhere near the right answers which are 30km/h and 270km/h

I have no clue what I am doing wrong. It could be the equations but I am not sure.

thanks!

 

[galactus]

This is not a differential equation, merely an algebra problem. I am moving it to Intermediate algebra.

Let r=planes rate and y=wind speed.

With the wind: \(\displaystyle \frac{600}{2}=r+y\)

Against the wind: \(\displaystyle \frac{600}{2.5}=r-y\)

Solve away.

 

[lyssa]

thanks so much.