math
posted by Laci .
I am having trouble with this motion problem.A jet travels 1,890 miles in 3 hours. flying against the same wind,the plane makes a return trip in 3 1/2 hours.Find the wind speed and the plane`s airspeed.My book gives the answer,but I just can not understand the concept of how they get the problem.Thanks for any help I can get.

(V+W)3=1890
(VW)3.5=1890
divide the top equation by 3, and the second equation by 3.5
V+W=630
VW=540
add the equations
2V=1170
solve for V, W
Take if from here.