Additive Identity

a + 0 = a

Example: If a = 8, we have 8 + 0 = 8

Additive Inverse

a + (-a) = 0

Example: If a = 8, we have 8 + (-8) = 8 – 8 = 0

Associative of Addition

(a + b) + c = a + (b + c)

Example:

If a = 2, b= 3 and c = 4, we have: (2 + 3) + 4 = 2 + (3 + 4) <=> 5 + 4 = 2 + 7

Commutative of Addition

a + b = b + a

Example:

If a = 3 and b = 5, we have: 3 + 5 = 5 +3 = 8

Definition of Subtraction

a - b = a + (-b)

Example:

If a = 3 and b = 4 we have 3 - 4 = 3 + (-4)

If a = -1and b = -3 we have -1 - (-3) = -1 + 3