The sum of the numerator and denominator of a fraction is 19. If 7 is added to the numerator, the value of the fraction is exactly 1. What is the original fraction?
一个分数的分子、分母的和是19，如果分子加上7，分数值正好是1，这个分数原来是多少．
<gadget id="calculator">19 + 7</gadget>
<output>26</output>

<gadget id="calculator">26 / 2</gadget>
<output>13</output>

<gadget id="calculator">13 - 7</gadget>
<output>6</output>

<gadget id="calculator">6 / 13</gadget>
<output>6/13 = around 0.461538</output>

<result>6/13 = around 0.461538</result>