0.8*(x-0.2)=1.
0.8*(x-0.2)=1．
<gadget id="calculator">0.8 * 0.2</gadget>
<output>0.16</output>

<gadget id="calculator">0.16 + 1</gadget>
<output>1.16</output>

<gadget id="calculator">1.16 / 0.8</gadget>
<output>1.45</output>

<result>1.45</result>