Two engineering teams jointly build a project. Team A completes (1/5) of this project every day, and team B completes (1/7) of this project every day. The two engineering teams can complete several parts of this project in one day. How much?
两个工程队共建一项工程，甲队每天完成这项工程的(1/5)，乙队每天完成这项工程的(1/7)，两个工程队一天可以完成这项工程的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(1/5) + (1/7)</gadget>
<output>12/35 = around 0.342857</output>

<result>12/35 = around 0.342857</result>