The existing cargo is 73 tons. It is planned to use two types of trucks with a load capacity of 7 tons and 5 tons to transport away at one time, and each truck must be filled. It is known that the fare for each truck with a load capacity of 7 tons is 65 yuan. The freight for a truck with a load capacity of 5 tons is 50 yuan per truck. How much is the most economical freight?
现有货物73吨，计划用载重量分别为7吨和5吨的两种卡车一次运走，且每辆都要装满，已知载重量为7吨的卡车每车车费为65元，载重量为5吨的卡车每车运费50元，问最省也要用运费多少元？
<gadget id="calculator">65 * 9</gadget>
<output>585</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">585 + 100</gadget>
<output>685</output>

<result>685</result>