For a fraction, the sum of the numerator and denominator is 23. If the denominator is increased by 17, the sub-fraction is (1/4), what is the original fraction?
某分数，分子分母之和为23，若把分母增加17，次分值为(1/4)，则原分数为多少．
<gadget id="calculator">23 + 17</gadget>
<output>40</output>

<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">40 * (1/5)</gadget>
<output>8</output>

<gadget id="calculator">40 - 8</gadget>
<output>32</output>

<gadget id="calculator">32 - 17</gadget>
<output>15</output>

<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>