writing a multi step equation for a real world solution.

Question

The family trip to grandmas consisted of both a train ride and a car ride. The average speed of the train ride was 78 miles per hour, and the average speed of the car ride was 56 miles per hour. The entire trip lasted 10 hours. Let x be the number of hours the train ride lasted. Write an expression for the total distance of the trip, in miles.

Answer 1

d = total distance in miles

x = duration of train ride

v = speed of train = 78 mph

u = speed of car = 56 mph

Total duration of trip = 10 hrs

d = vx + u(10 - x)

d = 78x + 56(10 - x)