Hey, Guys. I'm having trouble with sub subtraction here. If X = {1, 2, 3} and Y = {4, 5, 6}, then what is X-Y? I'm confused here.
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X is a set containing the elements 1, 2, and 3.
Y is a set containing the elements 4, 5, and 6.
Set subtraction removes common elements. Since X and Y have no elements in common, X - Y is simply equal to X.
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Following from the definition of set unions, X ∪ Y = {1, 2, 3, 4, 5, 6}.
So from what we know about set subtractions, you should be able to work out that Z - (X ∪ Y) subtracts ALL elements from Z, so what you end up with is an empty set.
Set subtraction:
http://www.mathwords.com/s/set_subtracti…
Set union:
http://www.mathwords.com/u/union.htm
Y is a set containing the elements 4, 5, and 6.
Set subtraction removes common elements. Since X and Y have no elements in common, X - Y is simply equal to X.
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Following from the definition of set unions, X ∪ Y = {1, 2, 3, 4, 5, 6}.
So from what we know about set subtractions, you should be able to work out that Z - (X ∪ Y) subtracts ALL elements from Z, so what you end up with is an empty set.
Set subtraction:
http://www.mathwords.com/s/set_subtracti…
Set union:
http://www.mathwords.com/u/union.htm
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{1-4,2-5,3-6} = {-3,-3,-3}