SOLUTION: Use a system of linear equations for the following question: A freight train and a passenger train leave Memphis, Tennessee at the same time, traveling in opposite directions. T

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Question 921957: Use a system of linear equations for the following question:
A freight train and a passenger train leave Memphis, Tennessee at the same time, traveling in opposite directions. The freight train is traveling 15 mph slower than the passenger train. Find the rate of each train if the distance between them is 525 after 5 hours.


I know how to answer this using one variable, but my professor wants a system of linear equations (two variables).
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
let y be the raate of the freight train and x be the rate of the passenger train, then we have two formulas
y = x - 15
5y + 5x = 525
substitute for y in second equation
5(x-15) +5x = 525
5x - 75 +5x = 525
10x = 600
x = 60 mph and y = 45 mph