When a=3, b=4, what is the result of 2a+4b?
当a=3，b=4时，2a+4b的结果是多少．
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">6 + 16</gadget>
<output>22</output>

<result>22</result>