Mr. Nelson sold 84 bags of popcorn in 7 hours. At this rate, how many bags of popcorn will Mr. Nelson sell in 12 hours?

At a local museum, the total price for one adult and one child is $11. mrs. smith paid for herself and her three children. she spent $19. record the system of equations to be solved and then find the price of an adult and child ticket using either elimination or substitution.