The parent function f(x)=x^2 is reflected across the x-axis, vertically stretched by a factor of 3, and translated right 7 units to create g(x). Use the description to write the quadratic function in vertex form.

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?