Jiuqing Village repaired a section of road, (1/4) repaired this section of road in the first week, and (2/7) repaired this section of road in the second week. In the past two weeks, I have repaired 2 kilometers more than the first week. How long is this road in kilometers?
久青村维修一段公路，第一周修了这段公路的(1/4)，第二周修了这段公路的(2/7)．这两周比第一周多修了2千米．这段公路全长多少千米？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

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

<result>7</result>