The length of a rope is equal to (3/5) of its own length plus (2/5) 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(3/5)加上(2/5)米，这绳子长多少米．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / (2/5)</gadget>
<output>1</output>

<result>1</result>