It takes a car 4.5 hours to drive from place A to place B. At the beginning, it travels 45 kilometers per hour, and after 1.8 hours, it travels an average of 35 kilometers per hour for the remaining distance. On average, how many kilometers per hour does the car travel from A to B?
一辆汽车从甲地开往乙地，一共用了4.5小时，开始每小时行45千米，行了1.8小时，剩下的路程平均每小时行35千米．这辆汽车从甲地到乙地平均每小时行多少千米？
<gadget id="calculator">45 * 1.8</gadget>
<output>81</output>

<gadget id="calculator">4.5 - 1.8</gadget>
<output>2.7</output>

<gadget id="calculator">35 * 2.7</gadget>
<output>94.5</output>

<gadget id="calculator">81 + 94.5</gadget>
<output>175.5</output>

<gadget id="calculator">175.5 / 4.5</gadget>
<output>39</output>

<result>39</result>