A bus travels from A to B on the first day (1/5) of the whole journey, and on the second day it travels 450km. At this time, the ratio of the traveled distance to the remaining distance is 7:3. How many kilometers away are the places?
一辆客车从甲地到乙地，第一天行了全程的(1/5)，第二天行了450km，这时已行路程和剩下路程的比是7：3，甲、乙两地相距多少千米？
<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(7/10) - (1/5)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">450 / (1/2)</gadget>
<output>900</output>

<result>900</result>