It means that given a set, if x and y are any members of the set then x+y is also a member of the set.
For example, positive integers are closed under addition, but they are not closed under subtraction, since 5 and 8 are members of the set of positive integers but 5 - 8 = -3 is not a positive integer.
Identity of addition means the answer and then add
The word 'plus' implies the process of addition.
The word is spelt as you have done in the question.
the addition
The closure of the school made the stuents sad. The early closure of the bank meant that I could not apply for a loan that day.
The general definition for the word occlusion refers the obstruction or a closure of a passageway or vessel. It can also mean to the occlusion of air masses.
"plus" It usually indicates addition.
Closure
Open or separated in a structure that can reasonably be expected to be capable of closure or connection without major structural modifications.
Identity properties do not change a number. What can you add to a number that doesn't change it? 0 So the addition property for zero is additive identity.
This question cannot be answered. There is no such word as "Comunitive" and so "the Comunitive Property of addition" does not exist. One possible alternative is the "commutative" property, but that is only of marginal relevance in terms of the given expression. Thus, it is not at all clear what property the question is about and why any such property should be invoked.
The Michael Jackson memorial was partially intended to give the public some closure in dealing with his untimely demise.