Cars A and B leave opposite cities at the same time from cities A and B. The speed of car B is (4/5) that of car A. The two cars meet at a distance of 12 kilometers from the midpoint. What is the distance in miles between A and B?
甲、乙两车同时从A、B两城相对开出，乙车的速度是甲车的(4/5)，两车在距离中点12千米处相遇．A、B两城相距多少千米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(1/2) - (4/9)</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">12 / (1/18)</gadget>
<output>216</output>

<result>216</result>