Final answer:
The student's displacement from the starting position is 75 meters west.
Step-by-step explanation:
To find the displacement of the student, we need to add the two vectors representing the distance moved south and east.
If we consider south as the negative y-axis and east as the positive x-axis, the displacement vector can be found by adding the two vectors:
Displacement = 30 m south - 45 m east
Displacement = -30 m - 45 m
Displacement = -75 m
Therefore, the student's displacement from the starting position is 75 meters west.