What is 0.4 × 16.21 = ?

If x=-3 is the only x-intercept of the graph of a quadratic equation, which statement best discribes the discriminant of the equation?

Plzzz answer both questions and i will give you 100 points

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.