Question 1052422
<pre><b>
B = {v | v is less than or equal to 1}

B has this number line graph:

<===============&#9787;---------------------------------
-4 -3 -2 -1  0  1  2  3  4  5  6  7  8  9 10 11 12

C = {v | v is less than 9}

C has this number line graph:

<=======================================o---------
-4 -3 -2 -1  0  1  2  3  4  5  6  7  8  9 10 11 12

To find B&#8746;C put them together and include everything
that is in one set or the other or both:

<===============&#9787;
<=======================================o---------
-4 -3 -2 -1  0  1  2  3  4  5  6  7  8  9 10 11 12

All of B is included in C, so the answer is just the
same as C, and the interval notation is

{{{matrix(1,5,"(",-infinity,",",9,")")}}}

Notice the parenthesis ")" on the right because 9 is NOT
included.]

To find B&#8745;C put ONLY include everything
that is in both sets:

<===============&#9787;
<=======================================o---------
-4 -3 -2 -1  0  1  2  3  4  5  6  7  8  9 10 11 12

We cannot include the interval from 1 to 9 because it
is not in BOTH sets.  All of C is included in B, so the 
answer is just the same as B, and the interval notation 
is:

{{{matrix(1,5,"(",-infinity,",",1,"]")}}}

Notice the bracket "]" on the right because 1 IS
included.]

Edwin</pre></b></font>