5. Martha leaves Carcar to visit a friend in Argao. She travels 250 km due South but then back-track North 100 km to pick up an friend. What is the total displacement of Martha?
A. 350 m South
C. 350 m South
B. 50 m North
D. 150 m North

9. If a biker rides West at 50 miles from his starting position, then turns and bikes back East 80 miles. What is his net displacement?
A. 130 miles
B. 30 miles
C. 30 miles
D. cannot be determined

Please help me po, thank you in advance^ω^​