A road repair team repaired a road. On the first day, it repaired 1/4 of the total length, and on the second day, it repaired 20% of the total length. It is known that the first day was 84 meters longer than the second day. How much rice?
某修路队修一条公路，第一天修了全长的(1/4)，第二天修了全长的20%，已知第一天比第二天多修了84米，第一天修路多少米？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">84 / (1/20)</gadget>
<output>1_680</output>

<gadget id="calculator">1_680 * (1/4)</gadget>
<output>420</output>

<result>420</result>