For a simple fraction, the difference between the numerator and the denominator is 4. If 9 is subtracted from both the numerator and the denominator, the resulting fraction is (7/9). What is the simplest fraction?
一个最简分数，分子和分母相差4，如果分子和分母都减去9，得到的分数是(7/9)，这个最简分数是多少．
<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">(7/9) * 4</gadget>
<output>28/9 = around 3.111111</output>

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

<gadget id="calculator">(28/9) - 7</gadget>
<output>-35/9 = around -3.888889</output>

<gadget id="calculator">9 + (-35/9)</gadget>
<output>46/9 = around 5.111111</output>

<gadget id="calculator">1 - (7/9)</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(46/9) / (2/9)</gadget>
<output>23</output>

<gadget id="calculator">23 + 4</gadget>
<output>27</output>

<gadget id="calculator">(46/9) / (2/9) / 27</gadget>
<output>23/27 = around 0.851852</output>

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