Which of the following equations below has exactly one solution?

What is the value of x in the diagram below?

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

Complete the equation of the line through (−10,3) and (−8,−8). use exact numbers.