Question 332153
Given these sets:
A = {1, 2, 3, 4}
B = {3, 4, 5, 6, 7}
C = {3, 5, 7, 9}

List the elements of this set
B ∩ (A U C)
Do not skip to the answer. Show your work, step by step
<pre><font size = 4 color = "indigo"><b>
---------------------------------------

B &#8745; (A U C)

Substitute the sets for the letters:

{3, 4, 5, 6, 7} &#8745; ({1, 2, 3, 4} U {3, 5, 7, 9}}

We do the parentheses first:

{1, 2, 3, 4} U {3, 5, 7, 9} means to list every element
that is in one of the two sets ONCE only, which is {1, 2, 3, 4, 5, 7, 9} 

So replace the parenthetical part, so we have: 

{3, 4, 5, 6, 7} &#8745; {1, 2, 3, 4, 5, 7, 9} 

That means to list only those elements that are in common
to the two sets:

{3, 4, 5, 7} 

That's the final answer.  

Edwin</pre>