Look at pic 10 pts will mark brainilest WILL HELP OUT W 3 QUESTIONS

Find the solution of this system of equation -7x+y=-20 9x-3y=36

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?

In the diagram, be and ad pass throughthe center of circle o, and the area ofsector aoc is 47.45 square units. what isthe area of sector boc? use the value =3.14, and round your answer to two decimalplaces.22.33 square units25.12 square units