<PRE><B>Question 864604</B>
B &amp;#8745; C is the set of things that are in BOTH set B AND set C



Only the number 5 is in BOTH set B AND set C. So this means B &amp;#8745; C = {5}



A &amp;#8746; (B &amp;#8745; C) turns into A &amp;#8746; {5}



That turns into {1, 2, 3, 4} &amp;#8746; {5} after you replace A with what it is defined to be. Finally you combine the two sets to get this final answer &lt;font color=&quot;red&quot;&gt;{1, 2, 3, 4, 5}&lt;/font&gt;



This means,  A &amp;#8746; (B &amp;#8745; C) = &lt;font color=&quot;red&quot;&gt;{1, 2, 3, 4, 5}&lt;/font&gt;



Note: we remove any duplicates. Since there are none, we don&#39;t have to worry about that for now.</PRE>