Xiaoliang miscalculated 5*(□+4) into 5*□+4, how much difference is the result from the correct answer
小亮把5*(□+4)错算成5*□+4，结果与正确答案相差多少
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<result>16</result>