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 120x−7=150x−9 ; x=15 120 x minus 7 equals 150 x minus 9 ; x equals 15 120−7x=150−9x ; x=15 120 minus 7 x equals 150 minus 9 x ; x equals 15 120+7x=150+9x ; x=−15 120 plus 7 x equals 150 plus 9 x ; x equals negative 15 120−7x=150−9x ; x=10 120 minus 7 x equals 150 minus 9 x ; x equals 10

1 answer

To find when the two popcorn machines will have the same amount of popcorn left, we can set up an equation based on their capacities and sales rates.

Let \( x \) be the number of hours after which we are measuring the amount of popcorn left.

For Movie Theatre A:

  • Initial popcorn: 120 gallons
  • Popcorn sold: 7 gallons per hour
  • Amount left after \( x \) hours: \( 120 - 7x \)

For Movie Theatre B:

  • Initial popcorn: 150 gallons
  • Popcorn sold: 9 gallons per hour
  • Amount left after \( x \) hours: \( 150 - 9x \)

Now we can set the two expressions equal to each other:

\[ 120 - 7x = 150 - 9x \]

Now, we will solve for \( x \):

  1. Start by adding \( 9x \) to both sides:

\[ 120 - 7x + 9x = 150 \]

  1. This simplifies to:

\[ 120 + 2x = 150 \]

  1. Next, subtract 120 from both sides:

\[ 2x = 30 \]

  1. Finally, divide by 2:

\[ x = 15 \]

Thus, the solution to the equation is \( x = 15 \).

This means that in 15 hours, both popcorn machines will have the same amount of popcorn left.