The road construction team repaired a road. On the first day, they repaired (9/20) kilometers, and on the second day they repaired (3/20) kilometers less than the first day. How many kilometers did you build in two days?
修路队修一条路，第一天修了(9/20)千米，第二天比第一天少修了(3/20)千米．两天一共修了多少千米？
<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(9/20) - (3/20)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) + (9/20)</gadget>
<output>3/4 = around 0.75</output>

<result>3/4 = around 0.75</result>