It takes 12 days for team A to do a project alone, and 8 days for team B to do it alone. How many days will it take for the two teams to work together? How many. (Only the column formula does not count)
一项工程甲队单独做要12天，乙队单独做要8天，两队合做要几天完成？多少．(只列式不计算)
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/12) + (1/8)</gadget>
<output>5/24 = around 0.208333</output>

<gadget id="calculator">1 / (5/24)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>