Add 2 to the denominator of a fraction to get (7/9), and add 3 to the denominator to get (3/4). What was the original score.
将一个分数的分母加上2得(7/9)，分母加上3得(3/4)．原来的分数是多少．
<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">9 / 7</gadget>
<output>9/7 = around 1.285714</output>

<gadget id="calculator">(4/3) - (9/7)</gadget>
<output>1/21 = around 0.047619</output>

<gadget id="calculator">1 / (1/21)</gadget>
<output>21</output>

<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">21 / (7/9)</gadget>
<output>27</output>

<gadget id="calculator">27 - 2</gadget>
<output>25</output>

<gadget id="calculator">21 / 25</gadget>
<output>21/25 = around 0.84</output>

<result>21/25 = around 0.84</result>