How many solutions does the system have? \begin{cases} y = -2x-4 y = 3x+3 \end{cases} ⎩ ​ y=−2x−4 y=3x+3 ​

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?