Let's break down each scenario and verify the equations provided:
1. Two machines at a factory filling cans of soup:
Given:
- Machine 1 (M1): 180 cans filled, filling rate = 15 cans/min
- Machine 2 (M2): 210 cans filled, filling rate = 12 cans/min
Let \( x \) represent the number of minutes passed.
Equation:
- Cans filled by M1 after \( x \) minutes: \( 180 + 15x \)
- Cans filled by M2 after \( x \) minutes: \( 210 + 12x \)
Set them equal to find when they will have the same number of cans: \[ 180 + 15x = 210 + 12x \]
Solving this leads us to: \[ 15x - 12x = 210 - 180 \] \[ 3x = 30 \] \[ x = 10 \]
So the correct equation is \( 180 + 15x = 210 + 12x \).
2. Movie Theatre A and B with popcorn machines:
Given:
- Theatre A: 100-gallon capacity, sells 3 gallons/hour
- Theatre B: 150-gallon capacity, sells 5 gallons/hour
Let \( x \) represent the number of hours passed.
Equation:
- Popcorn left in Theatre A after \( x \) hours: \( 100 - 3x \)
- Popcorn left in Theatre B after \( x \) hours: \( 150 - 5x \)
Set them equal to find when they will have the same amount of popcorn left: \[ 100 - 3x = 150 - 5x \]
Solving this leads us to: \[ 5x - 3x = 150 - 100 \] \[ 2x = 50 \] \[ x = 25 \]
So the correct equation is \( 100 - 3x = 150 - 5x \).
3. Ice cream machines (vanilla and chocolate):
Given:
- Vanilla machine: 180-cup capacity, sells 20 cups/day
- Chocolate machine: 140-cup capacity, sells 16 cups/day
Let \( x \) represent the number of days passed.
Equation:
- Ice cream left in vanilla machine after \( x \) days: \( 180 - 20x \)
- Ice cream left in chocolate machine after \( x \) days: \( 140 - 16x \)
Set them equal: \[ 180 - 20x = 140 - 16x \]
Solving this leads us to: \[ -20x + 16x = 140 - 180 \] \[ -4x = -40 \] \[ x = 10 \]
So the correct equation is \( 180 - 20x = 140 - 16x \).
4. Two machines filling cans of soup:
Given:
- Machine 1: 92 cans filled, filling rate = 16 cans/min
- Machine 2: 104 cans filled, filling rate = 13 cans/min
Let \( x \) represent the number of minutes passed.
Equation:
- Cans filled by M1 after \( x \) minutes: \( 92 + 16x \)
- Cans filled by M2 after \( x \) minutes: \( 104 + 13x \)
Set them equal: \[ 92 + 16x = 104 + 13x \]
Solving this leads us to: \[ 16x - 13x = 104 - 92 \] \[ 3x = 12 \] \[ x = 4 \]
So the correct equation is \( 92 + 16x = 104 + 13x \).
5. Movie Theatre A and B with popcorn machines:
Given:
- Theatre A: 120-gallon capacity, sells 7 gallons/hour
- Theatre B: 150-gallon capacity, sells 9 gallons/hour
Let \( x \) represent the number of hours passed.
Equation:
- Popcorn left in Theatre A after \( x \) hours: \( 120 - 7x \)
- Popcorn left in Theatre B after \( x \) hours: \( 150 - 9x \)
Set them equal: \[ 120 - 7x = 150 - 9x \]
Solving this leads us to: \[ 9x - 7x = 150 - 120 \] \[ 2x = 30 \] \[ x = 15 \]
So the correct equation is \( 120 - 7x = 150 - 9x \).
In summary, here’s the correct approach for each situation and the derived equations when the machines would have the same amount:
- From soup machines: \( 180 + 15x = 210 + 12x \)
- From popcorn machines: \( 100 - 3x = 150 - 5x \)
- From ice cream machines: \( 180 - 20x = 140 - 16x \)
- From the second soup machines: \( 92 + 16x = 104 + 13x \)
- From the second popcorn machines: \( 120 - 7x = 150 - 9x \)
The corresponding solutions are:
- \( x = 10 \)
- \( x = 25 \)
- \( x = 10 \)
- \( x = 4 \)
- \( x = 15 \)