To build a road, the daily repair is 40 kilometers more than the whole road (1/70), and it took 50 days to finish the repair. How many kilometers is this road?
修一条公路，每天修的比全路的(1/70)还多40千米，修了50天正好修完．这条公路长多少千米．
<gadget id="calculator">1 / 70</gadget>
<output>1/70 = around 0.014286</output>

<gadget id="calculator">(1/70) * 50</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">50 / (2/7)</gadget>
<output>175</output>

<gadget id="calculator">40 * 175</gadget>
<output>7_000</output>

<result>7_000</result>