A piece of iron wire uses (3/7) meters for the first time, and (1/7) meters more than the second time, how much meter is used for the two times?
一根铁丝，第一次用去(3/7)米，比第二次多用去(1/7)米，两次一共用去多少米？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

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

<gadget id="calculator">(3/7) - (1/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(3/7) + (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>