Question 921957
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