For a section of road, the ratio of the repaired length to the unrepaired length is 3:5. If another 55 meters are repaired, the repaired length will account for the total length (4/7). How long is this road?
一段公路，已修的长度与未修的长度的比是3：5，如果再修55米，已修的长度就占全长的(4/7)．这段公路有多长？
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(4/7) - (3/8)</gadget>
<output>11/56 = around 0.196429</output>

<gadget id="calculator">55 / (11/56)</gadget>
<output>280</output>

<result>280</result>