X-(3/4) X=(2/5).
Ⅹ-(3/4)Ⅹ=(2/5)．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<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">(2/5) / (1/4)</gadget>
<output>8/5 = around 1.6</output>

<result>8/5 = around 1.6</result>