Atrain travels 56 km east from its starting position. its starting point is 45 km east of its station. what is its final displacement relative to the station?

101km

Explanation:

If the train had started its journey starting from the station, its displacement would be 56km, but because the train began its journey 45km east from the station, what we must do is add the 56 km traveled to its initial position that is 45km (we can add them because both distances are on the same direction east):

the final displacement relative to the station is 101km to the east.

it is a negative acceleration