The sum of the denominator and the numerator of a fraction is 171. After dividing it, we get (7/12). What is the original fraction?
一个分数的分母和分子的和是171，约分后得(7/12)，原来这个分数是多少．
<gadget id="calculator">7 + 12</gadget>
<output>19</output>

<gadget id="calculator">7 / 19</gadget>
<output>7/19 = around 0.368421</output>

<gadget id="calculator">12 / 19</gadget>
<output>12/19 = around 0.631579</output>

<gadget id="calculator">171 * (12/19)</gadget>
<output>108</output>

<gadget id="calculator">(7/19) / 108</gadget>
<output>7/2_052 = around 0.003411</output>

<gadget id="calculator">171 * (7/2_052)</gadget>
<output>7/12 = around 0.583333</output>

<result>7/12 = around 0.583333</result>