Question

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
C ∩ (AB)
please show your work as I do not know how to figure this out
Thank you in advance for all of your help

Answer 1

what is (AB) represent ?

Answer 2

AxB would be meaningless in this context

A times B is equally as meaningless

Answer 3

I assume there is a missing operator notation ...

Answer 4

if it helps; use:

u for \(\cup \)

n for \(\cap \)

Answer 5

please forgive me it should read C ∩ (A ᴜ B)

Answer 6

its best to determine the (stuff) first then

that "U" means the we combine all the elements of A and B together into one massive set of elements:

"proper" set notation is to only post an element once, dont double them up.

so, here is the way i like to write it

A = {1, 2, 3, 4,}
U B = { 3, 4, 5, 6, 7}
----------------------
AUB = {1, 2, 3, 4, 5, 6, 7}

Now we have to "n" it with C that symbols means that we only use the elements that the defined sets have in common. Again, I like to write one set under the other and for this operation I only copy the elements that ARE doubled.

AUB = {1, 2, 3, 4, 5, 6, 7}
nC = { 3, 5, 7, 9}
-------------------------
{ 3, 5, 7, }

So to clean it up; the final results would be:

Cn(AuB) = {3,5,7}