Originally Posted by
simond75 a o b = a + b + ab, a * b = a + b + 1
For each binary operations on Z, answer the following with explanations:
A) are the commutative?
B) are they associative?
C) Do thy have an identity element?
D) Are there inverses?
E) Is Z a group with respect to either of these operations?
*Z is of course the symbol for set of integers (with double lines in middle connector)