SOLUTION: Two planes leave an airport at the same time, one flying east and the other flying west. The eastbound plane travels 80 mph slower. They are 2880 mi apart after 4 hr. Find the spe

Algebra ->  Equations -> SOLUTION: Two planes leave an airport at the same time, one flying east and the other flying west. The eastbound plane travels 80 mph slower. They are 2880 mi apart after 4 hr. Find the spe      Log On


   

Question 501677: Two planes leave an airport at the same time, one flying east and the other flying west. The eastbound plane travels 80 mph slower. They are 2880 mi apart after 4 hr. Find the speed of each plane.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
West bound plane x mph
East bound plane x+ -80
..
They are going away from each other.

So add up their speed.

combined speed = x+x+-80
( 2 x + -80 )
Time = 4 hours
Distance = 2880 miles
Distance = speed * time
( 2 x -80 )* 4 = 2880
8 x -320 = 2880
8 x = 2880 + 320
8 x = 3200
/ 8
x= 400 mph West bound plane
East bound plane 400 + -80 = 320 mph