minimal fraction, after adding one of its fractional units, is 1, and after subtracting a fractional unit, it is (3/4). What is the simplest fraction?
一个最简分数，加上它的一个分数单位后是1，减去一个分数单位约分后是(3/4)，这个最简分数是多少．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

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

<gadget id="calculator">(1/4) / 2</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 - (1/8)</gadget>
<output>7/8 = around 0.875</output>

<result>7/8 = around 0.875</result>