The master and the apprentice complete a batch of parts together. The master makes 73 parts per hour, and the apprentice makes 52 parts per hour. When it is completed, the master makes 105 more parts than the apprentice. How many hours does it take for the master and the apprentice to complete the task? (column equation solution)
师徒两人共同完成一批零件，师傅每小时做73个，徒弟每小时做52个，完成时师傅比徒弟多做了105个，师徒两个完成任务的时间是多少个小时？(列方程解答)
<gadget id="calculator">73 - 52</gadget>
<output>21</output>

<gadget id="calculator">105 / 21</gadget>
<output>5</output>

<result>5</result>