For a fraction, the sum of the numerator and the denominator is 156, and after reduction, it is (4/9). What is the original fraction?
一个分数，分子和分母的和是156，约分后是(4/9)，原这个分数是多少．
<gadget id="calculator">4 + 9</gadget>
<output>13</output>

<gadget id="calculator">4 / 13</gadget>
<output>4/13 = around 0.307692</output>

<gadget id="calculator">156 * (4/13)</gadget>
<output>48</output>

<gadget id="calculator">48 / 112</gadget>
<output>3/7 = around 0.428571</output>

<result>3/7 = around 0.428571</result>