The difference in xy is 13.6, what is the difference if x is subtracted by 2 and y is increased by 2
x-y的差是13.6，如果x减去2，y增加2，差是多少
<gadget id="calculator">23.6 - 2</gadget>
<output>21.6</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">21.6 - 12</gadget>
<output>9.6</output>

<result>9.6</result>