Question 222404
Two planes leave an airport at the same time and fly in opposite directions. One of the planes is flying at 450 mph, and the other is flying 550 mph. In how many hours will they be 2,000 miles apart?


Step 1.  time = distance/speed or distance=speed*time


Step 2.  Let x be the number of hours that the two planes will be 2000 miles apart.


Step 3.  Let 450x be the distance traveled by the plane at 450 mph.


Step 4.  Let 550x be the distance traveled by the plane at 500 mph.



Step 5.  450x+550x=2000 be the total distance traveled by both planes.


Step 6.  Solving yields the following steps.


{{{1000x=2000}}}


Divide 1000 to both sides of the equation


{{{1000x/1000=2000/1000}}}


{{{x=2}}}


Check... 2*(550+450)=2000...which is a true statement.


Step 7.  ANSWER:  The time will take 2 hours when they are 2000 miles apart.


I hope the above steps were helpful.


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Good luck in your studies!


Respectfully,
Dr J