Question

Movie Theatre A has a popcorn machine with a 120-gallon capacity. It sells 7 gallons of popcorn per hour. Movie Theatre B has a popcorn machine with a 150-gallon capacity. It sells 9 gallons of popcorn per hour. Write and solve an equation to show when the two popcorn machines will have the same amount of popcorn left.(1 point)
Responses

120−7x=150−9x
; x=15

120 minus 7 x equals 150 minus 9 x ; x equals 15

120x−7=150x−9
; x=15

120 x minus 7 equals 150 x minus 9 ; x equals 15

120−7x=150−9x
; x=10

120 minus 7 x equals 150 minus 9 x ; x equals 10

120+7x=150+9x
; x=−15

Answer 1

Set amounts equal: 120 − 7x = 150 − 9x.
Solve: add 9x to both sides → 120 + 2x = 150. Subtract 120 → 2x = 30. So x = 15 hours.
(Each machine will have 15 gallons left: 120−7·15 = 150−9·15 = 15.)