In the urban area, the Passepartout project was carried out, and a highway was repaired (4/5) kilometers in the first week, (1/10) kilometers less in the second week than in the first week, and more in the third week than in the second week ( 1/2) kilometers, how many kilometers were repaired in the third week.
城区实施路路通工程改造，修了一条公路第一周修了(4/5)千米，第二周比第一周少修了(1/10)千米，第三周比第二周多修了(1/2)千米，第三周修了多少千米．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(4/5) - (1/10)</gadget>
<output>7/10 = around 0.7</output>

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

<gadget id="calculator">(7/10) + (1/2)</gadget>
<output>6/5 = around 1.2</output>

<result>6/5 = around 1.2</result>