Add 3 to a denominator to get (7/9), add 5 to the denominator to get (3/4), what is the original fraction?
给一个分母加3得(7/9)，分母加5得(3/4)，原分数是多少？
<gadget id="calculator">54 * 7</gadget>
<output>378</output>

<gadget id="calculator">378 / 9</gadget>
<output>42</output>

<gadget id="calculator">135 - 84</gadget>
<output>51</output>

<gadget id="calculator">42 / 51</gadget>
<output>14/17 = around 0.823529</output>

<result>14/17 = around 0.823529</result>