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AR15.COM
5/20/2011 8:06:45 AM EDT

I have a problem in my math homework that goes:

Let U = {1, 2, 3, 4, 5, 6, 7,8, 9, 10}, A= {3, 4, 5}, and B= {5, 6, 7}

Find A - B.

Either the teacher didn't cover it or I was looking down when he explained it, but I don't see how to subtract B from A when B is not a subset of A.

An explanation would be greatly appreciated.
5/20/2011 8:08:23 AM EDT
[#1]
288
5/20/2011 8:10:18 AM EDT
[#2]
Quoted:
288


Apparently you missed the part about an explanation.
5/20/2011 8:15:38 AM EDT
[#3]
"A union B" is the combination of A and B = {3,4,5,6,7}
"A intersection B" is the common overlap of A and B = {5}
"A subtract B" is all elements only in A = {3,4}
"A disjunction B" is all elements in either A or B but not both = {3,4,6,7}
5/20/2011 8:18:43 AM EDT
[#4]
Quoted:
"A union B" is the combination of A and B = {3,4,5,6,7}
"A intersection B" is the common overlap of A and B = {5}
"A subtract B" is all elements only in A = {3,4}
"A disjunction B" is all elements in either A or B but not both = {3,4,6,7}


5/20/2011 8:19:30 AM EDT
[#5]



Quoted:




"A subtract B" is all elements only in A = {3,4}



This is my answer as well.

B.S. Mathematics



 
5/20/2011 8:20:41 AM EDT
[#6]
I had to use this the other day to find the tax on my groceries.
5/20/2011 8:20:54 AM EDT
[#7]
Quoted:
Quoted:
"A union B" is the combination of A and B = {3,4,5,6,7}
"A intersection B" is the common overlap of A and B = {5}
"A subtract B" is all elements only in A = {3,4}
"A disjunction B" is all elements in either A or B but not both = {3,4,6,7}




Indeed.
5/20/2011 8:20:58 AM EDT
[#8]
Thanks, guys!
5/20/2011 8:22:11 AM EDT
[#9]
Quoted:

Quoted:

"A subtract B" is all elements only in A = {3,4}

This is my answer as well.
B.S. Mathematics
 


Mmm but you could sound so much smarter by saying the complement of B relative to A.