The fast and slow trains depart from the east and west cities at the same time and run toward each other. The express train travels 80 km per hour, and the slow train travels 65 km per hour. When they meet, the fast train travels 75 km longer than the slow train. Find the distance between the east and west cities.
快慢两车分别从东、西两城同时出发相向而行，快车每时行80km，慢车每时行65km，相遇时，快车比慢车多行75km．求东西两城距离．
<gadget id="calculator">80 + 65</gadget>
<output>145</output>

<gadget id="calculator">80 - 65</gadget>
<output>15</output>

<gadget id="calculator">75 / 15</gadget>
<output>5</output>

<gadget id="calculator">145 * 5</gadget>
<output>725</output>

<result>725</result>