Answer:
101km
Step-by-step 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.