There is a fraction whose sum of numerator and denominator is 50. After subtracting 7 from its numerator and denominator at the same time, the current fraction is equal to (4/5). What is the original fraction?
有一个分数，分子与分母的和是50，把它的分子和分母同时减去7后，现在的分数与(4/5)相等，原来的分数是多少？
<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<gadget id="calculator">50 - 14</gadget>
<output>36</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">36 * (4/9)</gadget>
<output>16</output>

<gadget id="calculator">16 + 7</gadget>
<output>23</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">36 * (5/9)</gadget>
<output>20</output>

<gadget id="calculator">20 + 7</gadget>
<output>27</output>

<gadget id="calculator">23 / 27</gadget>
<output>23/27 = around 0.851852</output>

<result>23/27 = around 0.851852</result>