What is the solution of the equation x-20=20-x?
方程x-20=20-x的解是x=多少
<gadget id="calculator">20 + 20</gadget>
<output>40</output>

<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<result>20</result>