WILL GIVE BRAINLIEST if you show your work

Monica build a remote control toy airplane for science project to test the plane she launched it from the top of a building the plane travel a horizontal distance of 50 feet before landing on the ground a quadratic function which models the height of the plane in feet relative to the ground at a horizontal distance of x feet from the building is shown

Multiply. write your answer in simplest form. 3/8 x 5/7

David leaves his house to go to school. he walks 200 meters west and 300 meters north. how far is david from his original starting point?