Find the missing number in this proportion.
? /8 =16/64

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

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.

Need me know if option a,b,c are wrong so ik its d