To build a road, the original plan was to build 0.56 kilometers per day, but the actual daily repair was 0.14 kilometers more than the original plan. After 7 days, there was still 3.5 kilometers left unrepaired. How long is this road in kilometers?
修一条公路，原计划每天修0.56千米，实际每天比原计划多修0.14千米，7天后还差3.5千米没有修，这条路长多少千米？
<gadget id="calculator">0.56 + 0.14</gadget>
<output>0.7</output>

<gadget id="calculator">0.7 * 7</gadget>
<output>4.9</output>

<gadget id="calculator">4.9 + 3.5</gadget>
<output>8.4</output>

<result>8.4</result>