" Show that the set "A={-1,0,1}" is not closed for addition."

Consider the following statement I. The set of positive powers of 2 is closed under multiplication. II. The set [1,0,-1] is closed under multiplication. III. The number 35 has exactly four divisors. IV. The set [1,0,-1] is closed under addition. Of the above statement

The set of integers in not closed under

Is the set A = {-2, -4, -6, -8,…………..} closed, under addition

Write two examples to show that: whole numbers are closed under addition.

Show that -a is not the inverse of a in N for the addition operation + on N and 1/a is not the inverse of a in N for multiplication operation xx on N, for a!=1 .

Show that -a is not the inverse of a in N for the addition operation + on N and 1/a not the inverse of a in N for multiplication operation on N , for a ne 1 .