To find out after how many days the rental car prices for A and B will be equal, we can set up the equations based on the given rates.
For rental car A:
- Initial cost: $100
- Daily cost: $10 per day
Let \( x \) be the number of days. Therefore, the total cost for rental car A can be expressed as: \[ \text{Cost of A} = 100 + 10x \]
For rental car B:
- Initial cost: $50
- Daily cost: $20 per day
The total cost for rental car B can be expressed as: \[ \text{Cost of B} = 50 + 20x \]
To find when the costs are equal, we set the two equations equal: \[ 100 + 10x = 50 + 20x \]
Now, we can solve this equation for \( x \):
- Subtract \( 10x \) from both sides: \[ 100 = 50 + 10x \]
- Subtract 50 from both sides: \[ 50 = 10x \]
- Divide by 10: \[ x = 5 \]
Interpretation of the Solution: The solution \( x = 5 \) means that after 5 days, the total rental prices for both car A and car B will be equal.
To verify this, we can calculate the costs for both cars after 5 days:
- Cost of car A after 5 days: \( 100 + 10(5) = 100 + 50 = 150 \)
- Cost of car B after 5 days: \( 50 + 20(5) = 50 + 100 = 150 \)
Thus, both costs are indeed equal at $150 after 5 days.
Therefore, the correct response is: \( 50 + 20x = 100 + 10x; x = 5; \) after 5 days the prices are equal.