((2+2x)/(x+1))=y, when x=0, what is y
((2+2x)/(x+1))=y，当x=0时，y为多少
<gadget id="calculator">2 * 0</gadget>
<output>0</output>

<gadget id="calculator">2 + 0</gadget>
<output>2</output>

<gadget id="calculator">0 + 1</gadget>
<output>1</output>

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

<result>2</result>