b. he is 140m west of the milestone, so that would be -140 m. (remember, displacement relates to only the final position)

c. since he began 140m west of the marker and ended up 320m east of the marker, the distance he traveled was 140m + 320m = +460m to the east. we just add his displacement from the previous run to this one, so we’ll get (-440m) + (460m) = +20m.

d. the distance can be solved by adding the absolute value, or the magnitude of their displacements. 440m + 460m = 900m.

Add 300 and 140. Figure out if the direction he is going is “positive” or “negative”.

No, I wouldn’t say “do your own homework”, but I would say “don’t lie about ‘need to check answers'”.