Page 71 - Algebra 1

L E S S O N Multiplying and Dividing Real Numbers 11
Warm Up
New Concepts
1. Vocabulary Two numbers with the same absolute value but different signs
(6)
are called (integers, opposites). Simplify each expression.
2. (-4) + (-4) + (-4) (5)
4. 54 (3)
3. -8 - 8 - 8 - 8 - 8 - 8 (6)
5. 25 (3)
The sum of three 2’s is 6 and the sum of two 3’s is 6. 2+2+2=6 3+3=6
Multiplication is a way to show repeated addition of the same number. The repeated addition above can be shown as multiplication of the same number.
3·2=6 or 2·3=6
The properties of real numbers apply to all real numbers, rational and irrational. Use these properties when evaluating and simplifying numeric and algebraic expressions.
The table shows some properties of multiplication when a and b are real numbers.
Math Reasoning
Analyze How are the Identity Property of Multiplication and the Identity Property of Addition alike?
Properties of Real Numbers
Multiplication Property of -1 For every real number a,
a · -1 = -1 · a = -a Example 9 · -1 = -1 · 9 = -9
For every real number a, Example 9·0=0
a·0=0
Multiplication Property of Zero
Inverse Property of Multiplication
For every real number a, where a ≠ 0,
a·_1 =_1 ·a=1 aa
Example 3·_1 =_1 ·3=1 33
Online Connection www.SaxonMathResources.com
56 Saxon Algebra 1