How is the definition of property similar in science and math

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.

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great

Combine like terms to create an equivalent expression. make sure to simplify coefficients and constants as well. -6/5-2/3v+4/15+1/3v