(x-5)*5-9=(x-12)*12.
(x-5)*5-9=(x-12)*12．
<gadget id="calculator">12 * 12</gadget>
<output>144</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">144 - 25 - 9</gadget>
<output>110</output>

<gadget id="calculator">12 - 5</gadget>
<output>7</output>

<gadget id="calculator">110 / 7</gadget>
<output>110/7 = around 15.714286</output>

<result>110/7 = around 15.714286</result>