For a fraction, the sum of the numerator and the denominator is 105, which is (3/4) after the division. What is the original fraction?
一个分数，分子、分母的和是105，约分后是(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) * 105</gadget>
<output>315/4 = around 78.75</output>

<gadget id="calculator">1 + (3/4)</gadget>
<output>7/4 = around 1.75</output>

<gadget id="calculator">(315/4) / (7/4)</gadget>
<output>45</output>

<gadget id="calculator">105 - 45</gadget>
<output>60</output>

<gadget id="calculator">(315/4) / (7/4) / 60</gadget>
<output>3/4 = around 0.75</output>

<result>3/4 = around 0.75</result>