Let's denote \( x \) as the number of miles driven.
For the first car rental company, the total cost \( C_1 \) can be expressed as: \[ C_1 = 35 + 0.10x \]
For the second car rental company, the total cost \( C_2 \) is: \[ C_2 = 25 + 0.15x \]
To find the mileage at which both companies charge the same amount, we set the two equations equal to each other: \[ 35 + 0.10x = 25 + 0.15x \]
Now, we can solve for \( x \). First, isolate the \( x \) terms on one side: \[ 35 - 25 = 0.15x - 0.10x \] \[ 10 = 0.05x \]
Next, solve for \( x \) by dividing both sides by 0.05: \[ x = \frac{10}{0.05} \] \[ x = 200 \]
Therefore, the price charged by each company will be the same when \( 200 \) miles have been driven.