After adding 2 to the numerator of a fraction, it is equal to 1. After adding 1 to the denominator, the ratio of the numerator to the denominator is 3:4. What is the original fraction?
一个分数的分子加上2后就等于1，分母加上1约分后分子与分母的比是3：4，原来这个分数是多少？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) * 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) + (3/4)</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(9/4) / (1/4)</gadget>
<output>9</output>

<gadget id="calculator">9 + 2</gadget>
<output>11</output>

<gadget id="calculator">(9/4) / (1/4) / 11</gadget>
<output>9/11 = around 0.818182</output>

<result>9/11 = around 0.818182</result>