What is 23.58 in word form

The parabola opens: y=√x-4 (principal square root) up down right left

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?

What is the the area of this triangle expressed as a monomial?