SOLUTION: Please help, been stuck on this all day, dont just need an answer, need help solving the problem so I can finish all the rest, Joe flew his small airplane 900 km in 5 hours with t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Please help, been stuck on this all day, dont just need an answer, need help solving the problem so I can finish all the rest, Joe flew his small airplane 900 km in 5 hours with t      Log On


   



Question 256754: Please help, been stuck on this all day, dont just need an answer, need help solving the problem so I can finish all the rest,
Joe flew his small airplane 900 km in 5 hours with the wind. He flew 700 km against the wind in 7 hours. Find the rate at which he flew in still air and the rate of the wind. I have to use this table to solve it
5(r+w)=900
7(r-w)=700

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
5(r+w)=900 You have got the hard part done already.
7(r-w)=700
.
5r+5w=900
7r-7w=700
.
7r=700+7w
r=100+w
.
5r+5w=900
5(100+w)+5w=900
500+5w+5w=900
10w+500=900
10w=400
w=40 kmph rate of the wind
r=140 kmph rate in still air