What is the difference between 3*(5+6) and 3*5+6?
3*(5+6)与3*5+6的差是多少．
<gadget id="calculator">5 + 6</gadget>
<output>11</output>

<gadget id="calculator">3 * 11</gadget>
<output>33</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">15 + 6</gadget>
<output>21</output>

<gadget id="calculator">33 - 21</gadget>
<output>12</output>

<result>12</result>