Just need help on 3, problem is included in picture

Johnny rode his bike to a friends house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was unable to play. what was his displacement for the total bike ride trip? what could you use as a reference point ? show the steps to solve this problem.

What is the solution for 6 - 7/8? explain the steps.

2pointswhat is the best next step in the construction of the perpendicular bisector ofab?