A car has traveled the entire distance (5/7) from place A to place B, which is 80 kilometers away from place B. How many kilometers are there between A and B?
一辆汽车从甲地开往乙地，已经行了全程的(5/7)，这是离乙地还有80千米．甲、乙两地相距多少千米？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">80 / (2/7)</gadget>
<output>280</output>

<result>280</result>