Two cars drive toward each other from A and B, which are 780 km apart, and meet each other in 6 hours. The fast car travels 10 km more than the slow car per hour. Find the speed of the slow car. (column equation solution)
两辆汽车从相距780km的甲乙两地相向而行，6h相遇，快车每小时比慢车多行驶10km．求慢车的速度．(列方程解答)
<gadget id="calculator">10 * 6</gadget>
<output>60</output>

<gadget id="calculator">780 - 60</gadget>
<output>720</output>

<gadget id="calculator">6 + 6</gadget>
<output>12</output>

<gadget id="calculator">720 / 12</gadget>
<output>60</output>

<result>60</result>