For a section of road, it will take 6 days for Team A to work alone, and it will take 9 days for Team B to work alone. A and B work together for 2 days, and A alone completes the rest. How many days will it take?
一段公路，甲=队单独干要6天铺完，乙队单独干要9天铺完．甲乙合做2天，余下的由甲单独完成，还需多少天铺完？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/6) + (1/9)</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">(5/18) * 2</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 - (5/9)</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(4/9) / (1/9)</gadget>
<output>4</output>

<result>4</result>