A and B start from A and B at the same time, walk toward each other, and meet each other within an hour. The ratio of the distance traveled by A and B when they meet is 4:5, and B travels 5 kilometers per hour, how many kilometers is the distance from A to B?
甲、乙两人同时从A、B地出发，相向而行，1小时相遇．相遇时甲、乙所走的路程比是4：5，乙每小时走5千米，A到B有多少千米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">5 * (4/5)</gadget>
<output>4</output>

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

<gadget id="calculator">9 * 1</gadget>
<output>9</output>

<result>9</result>