Answer:
identity - addition
Step-by-step explanation:
Properties of Numbers
Addition
Closure:
If a R and b R, then a + b is a unique element of R.
Commutative:
a + b = b + a.
Associative:
a + (b + c) = (a + b) + c.
Identity:
a + 0 = a.
Additive Inverse:
a + (-a) = 0.
