x-(2/7)x=(1/14).
x-(2/7)x=(1/14)．
<gadget id="calculator">1 / 14</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">(1/14) / (5/7)</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>