If the taxi travels within 10 kilometers, the starting price for the first 3 kilometers is 13 yuan, and the price is 2 yuan for every 1 kilometer after that. How much does Xiaoya need to pay for traveling 9 kilometers by car?
出租车行驶10千米之内，前3千米起步价为13元，以后每行驶1千米为2元，小亚坐车行驶9千米，需付多少元．
<gadget id="calculator">9 - 3</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">12 + 13</gadget>
<output>25</output>

<result>25</result>