For a fraction, the sum of the numerator and the denominator is 25, and after the numerator is increased by 9, the fraction is equal to 1. What is the original fraction?
一个分数，分子与分母的和是25，并且分子增加9后，这个分数就等于1，这个分数原来是多少．
<gadget id="calculator">25 - 9</gadget>
<output>16</output>

<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">25 - 8</gadget>
<output>17</output>

<gadget id="calculator">16 / 2 / 17</gadget>
<output>8/17 = around 0.470588</output>

<result>8/17 = around 0.470588</result>