A and B start from opposite places at the same time. When they meet, A travels 4 kilometers longer (7/15), and B travels at 80% of A's speed. How many kilometers are the distance between the two places?
甲乙两人同时从两地相对出发，相遇时甲行全程的(7/15)还多4千米，乙行走的速度是甲的80%，两地相距多少千米？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">(5/9) - (7/15)</gadget>
<output>4/45 = around 0.088889</output>

<gadget id="calculator">4 / (4/45)</gadget>
<output>45</output>

<result>45</result>