Page 40 - Math Booklet Prep1first part1_Neat

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Date :

Properties of addition operation in Z

If a, b, and care three integers, then integer addition has the following
properties:

Closure: The sum of any two integers is also an integer. (a+ b ? Z}

Commutative: a + b = b + a

Associative: (a + b) + c = a + (b + c)
Identity Element: The additive identity element is 0.

a + 0 =0 + a =a

Inverse Element: The additive inverse of a is -a.
a + (-a) = (-a) + a =0

subtracting two integers

• If a ? Z , b ? Z Then a - b = a + the additive inverse of b.

Examples

find the result of each of the

following :

(a) 9 - 5 (b) -7 -4

The Solution :

(a) 9 - 5 = 9 + (-5) = 4

(b)-7 - 4 = -7 + (-4) = -11

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