Answer:
The correct answer is 25x + 480 miles.
Explanation:
The family trip to Grandma's consisted of a train and car ride.
Average speed of the train ride is 73 miles per hours and average speed of the car ride is 48 mile per hours.
Total time taken for the whole trip is 10 hours. Let the rain ride lasted for x hours. So the car ride lasted for (10 - x) hours.
We know from the definition of distance traveled which is equal to speed times the time of the journey.
Distance traveled by the train is given by 73x miles.
Distance traveled by the car is given by 48( 10 - x ) miles.
Therefore total distance of the trip is given by 73x + 48( 10 - x ) = 25x + 480 miles.