χ-(7/8)x=(1/20).
χ-(7/8)x=(1/20)．
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">1 - (7/8)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/20) / (1/8)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>