SOLUTION: is (0,1,-1) closed under addition? ...and if you can explain how to do this, that would be great

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Question 160073: is (0,1,-1) closed under addition?
...and if you can explain how to do this, that would be great
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
0+1=1
1+(-1)=0
-1+0=-1


Notice how the sum of every pair of numbers is a number in the set {0,1,-1}. So this means that the set is closed under addition.


Remember, a set that is "closed" under addition means that you can add up ANY two numbers in that set and you will ALWAYS get a number in that set.