What is the solution to x + 8 = 19​

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

What are two numbers that have a sum of 15

Acone with radius 5 cm and height 12 cm how many cm ?