The length of a rope is equal to (5/7) of its own length plus (5/7) meters, how many meters is the length of the rope?
一根绳子的长度等于它本身长度的(5/7)加上(5/7)米，这绳子长多少米．
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(5/7) / (2/7)</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>