The height of a diver above the water is given by the quadratic function h(t)= -5t^2+5t+10, with t in seconds and h(t) meters. When will the diver reac maximun height

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?