I need help immediately pls !!

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 is the value of x in the equation (2)3) (x+6)= -18 a. -36 b. -33 c. -24 d. -18

The experience c-0.25c can be used to find the cost of an item on sale for 25% off which expression beloit equivalent to c-0.25c