find the approximate area of a circle with a diameter of 10 meters.
a: 3oo square meters
b: 78 square meters
c: 19 square meters
d: 142 square meters

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?