SOLUTION: 2 planes take off from the same airport at the same time flying in opposite directions. 1 plane travels at twice the speed of the other plane. After 3hrs, they are 1,620 miles ap

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Question 68378: 2 planes take off from the same airport at the same time flying in opposite directions. 1 plane travels at twice the speed of the other plane. After 3hrs, they are 1,620 miles apart. What is the average speed(rate)of each plane?
plane 1 = 2x
plane 2 = x
distance =1,620 miles
time = 3 hrs
r = d/t r = 1,620/3 or r = 1620 - 2x(3)
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
3(2X+X)=1620
3*3X=1620
9X=1620
X=1620/9
X=180 MPHFOR THE SLOW PLANE THUS THE FASTER OPLANE'S SPED IS
2*180=360 MPH
PROOF
3(180+360)=1620
3*540=1620
1620=1620