The number line shows how isa's bank balance decreased after writing several checks. which balance is \$86$86dollar sign, 86 more than the balance of -\$47.90−$47.90minus, dollar sign, 47, point, 90?

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.