If a girl is 3 and another one if 16 and 10 years pass by and the older one is double the other girls age how old are they

7x+8y=-18, 4x-9y=-3 solve the system of equations

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?

Write an inequality for this sentence the quotient of a number and -5 increased by 4 is at most 8