True or false? Natural numbers are closed under division

Negative numbers are closed under addition

Prime numbers are closed under subtraction

Write the equation for the parabola that has x− intercepts (−2,0) and (4,0) and y− intercept (0,4).

Is the power produced directly proportional to the wind speed, give reasons for your answer?

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.