To find when the two popcorn machines will have the same amount of popcorn left, we can set up an equation based on their starting capacities and their sales rates.
Let's denote \( x \) as the number of hours that have passed.
For Movie Theatre A:
- Starting capacity: 100 gallons
- Sales rate: 3 gallons per hour
- Amount of popcorn left after \( x \) hours: \( 100 - 3x \)
For Movie Theatre B:
- Starting capacity: 150 gallons
- Sales rate: 5 gallons per hour
- Amount of popcorn left after \( x \) hours: \( 150 - 5x \)
We want to find when the amount of popcorn left in both machines is equal, so we set the two expressions equal to each other:
\[ 100 - 3x = 150 - 5x \]
This equation can be rewritten as:
\[ 3x - 100 = 5x - 150 \]
So the correct response is:
3x - 100 = 5x - 150