To build a road, the full length (2/5) has been built, and there are still 7 meters away from the midpoint. How many meters is the total length of this road?
修一条路，已经修了全长的(2/5)，离中点还有7米，这条公路全长多少米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">7 / (1/10)</gadget>
<output>70</output>

<result>70</result>