Two cars, the fast and the slow, leave opposite places at the same time. The fast train travels 80 kilometers per hour, and the slow train travels 45 kilometers per hour. After the two cars arrive at the starting point of each other, they return immediately. When the two cars meet for the second time, the fast car travels 210 kilometers longer than the slow car. Find the distance between A and B.
快慢两车同时从甲乙两地相对开出，快车每小时行80千米，慢车每小时行45千米．两车到达对方的出发点后都马上返回，两车第二次相遇时，快车比慢车多行210千米．求甲乙两地之间的距离．
<gadget id="calculator">80 + 45</gadget>
<output>125</output>

<gadget id="calculator">80 - 45</gadget>
<output>35</output>

<gadget id="calculator">210 / 35</gadget>
<output>6</output>

<gadget id="calculator">125 * 6</gadget>
<output>750</output>

<gadget id="calculator">750 / 3</gadget>
<output>250</output>

<result>250</result>