Two trains departed from two places 432 kilometers apart at the same time, and the two trains met after 4 hours. The express train travels 60 kilometers per hour, how many kilometers per hour does the slow train travel? (Solution of column equation)
两列火车同时从相距432千米的两地相对开出，4小时后两车相遇．快车每小时行60千米，求慢车每小时行多少千米．(列方程解)
<gadget id="calculator">60 * 4</gadget>
<output>240</output>

<gadget id="calculator">432 - 240</gadget>
<output>192</output>

<gadget id="calculator">192 / 4</gadget>
<output>48</output>

<result>48</result>