To find the point where the costs from Company A and Company B are the same based on the number of miles driven, we can first set up the functions for each company's rental cost:
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Company A charges: \[ A(x) = 40 + 1x \] where \(A(x)\) is the total cost from Company A after driving \(x\) miles.
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Company B charges: \[ B(x) = 20 + 1.5x \] where \(B(x)\) is the total cost from Company B after driving \(x\) miles.
Next, we want to find the number of miles, \(x\), where \(A(x) = B(x)\): \[ 40 + x = 20 + 1.5x \]
Now, let's solve for \(x\):
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Subtract \(x\) from both sides: \[ 40 = 20 + 0.5x \]
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Subtract 20 from both sides: \[ 20 = 0.5x \]
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Multiply both sides by 2: \[ x = 40 \]
So, the two companies' total costs will be the same when Mia drives 40 miles.
Summary of Costs:
When \(x = 40\):
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Cost from Company A: \[ A(40) = 40 + 1(40) = 40 + 40 = 80 \]
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Cost from Company B: \[ B(40) = 20 + 1.5(40) = 20 + 60 = 80 \]
Both costs are $80 when 40 miles are driven.
Graphing the Functions:
To graph the functions:
- Company A: \(y = 40 + x\)
- Company B: \(y = 20 + 1.5x\)
For graphing:
- The y-intercept for Company A is 40 and the slope is 1.
- The y-intercept for Company B is 20 and the slope is 1.5.
When you plot these on a graph, you will see that the lines intersect at the point (40, 80). This is where both companies would charge the same amount, confirming \(x = 40\) miles.