A village builds a road (9/10) kilometers long. On the first day, (1/5) kilometers were built, and on the second day, (1/20) kilometers were repaired more than the first day. How many kilometers are left? build?
某村修一条长(9/10)千米的公路，第一天修了(1/5)千米，第二天比第一天多修(1/20)千米，还剩多少千米没有修？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

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

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/5) + (1/20) + (1/5)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">(9/10) - (9/20)</gadget>
<output>9/20 = around 0.45</output>

<result>9/20 = around 0.45</result>