The road repair team built a road. On the first day, it repaired the full length (1/2), and on the second day it repaired the rest (3/10), leaving 49 kilometers. How many kilometers is this road in total?
修路队修一条公路，第一天修了全长的(1/2)，第二天修了剩下的(3/10)，还剩49千米，这条公路一共多少千米？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">49 / (7/10)</gadget>
<output>70</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">70 / (1/2)</gadget>
<output>140</output>

<result>140</result>