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2.1 Properties of Real Numbers. Commutative Associative Identity + ×. Commutative Properties. Changing the order of the numbers in addition or multiplication will not change the result. Commutative Property of Addition states: 2 + 3 = 3 + 2 a + b = b + a.
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2.1 Properties of Real Numbers Commutative Associative Identity + ×
Commutative Properties • Changing the order of the numbers in addition or multiplication will not change the result. • Commutative Property of Addition states: 2 + 3 = 3 + 2 a + b = b + a. • Commutative Property of Multiplication states: 4 • 5 = 5 • 4 ab = ba.
Associative Properties • Changing the grouping of the numbers in addition or multiplication will not change the result. • Associative Property of Addition states: 3 + (4 + 5)= (3 + 4)+ 5 a + (b + c)= (a + b)+ c • Associative Property of Multiplication states: (2 • 3) • 4 = 2 • (3 • 4) (ab)c = a(bc)
Additive Identity Property • There exists a unique number 0 such that zero preserves identities under addition. a + 0 = a 0 + a = a • In other words adding zero to a number does not change its value.
Multiplicative Identity Property • There exists a unique number 1 such that the number 1 preserves identities under multiplication. a∙ 1 = a 1 ∙a = a • In other words multiplying a number by 1 does not change the value of the number.
State the property or properties that justify the following. 3 + 2 = 2 + 3 Commutative Property
State the property or properties that justify the following. 3 + (4 + 5) = (3 + 4) + 5 Associative Property
State the property or properties that justify the following. (5 + 2) + 9 = (2 + 5) + 9 Commutative Property
2. Which Property? 3 + 7 = 7 + 3 Commutative Property of Addition
3. Which Property? 8 + 0 = 8 Identity Property of Addition
5. Which Property? 6 • 4 = 4 • 6 Commutative Property of Multiplication