Team A has already paved (2/7), and Team B has paved this lawn more than Team A (1/5). Team A and Team B jointly pave a piece of lawn. What fraction of the lawn has been laid?
甲队已经铺了(2/7)，乙队比甲队多铺了这块草坪的(1/5)．甲乙两队合铺一块草坪．已经铺了这块草坪的几分之几？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/7) + (1/5) + (2/7)</gadget>
<output>27/35 = around 0.771429</output>

<result>27/35 = around 0.771429</result>