Solve the equation: 9*(20-x)=3.6.
解方程：9*(20-x)=3.6．
<gadget id="calculator">9 * 20</gadget>
<output>180</output>

<gadget id="calculator">180 - 3.6</gadget>
<output>176.4</output>

<gadget id="calculator">176.4 / 9</gadget>
<output>19.6</output>

<result>19.6</result>