((x)/5)-((x)/6)=0.4.
((x)/5)-((x)/6)=0.4．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/5) - (1/6)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">0.4 / (1/30)</gadget>
<output>12</output>

<result>12</result>