Page 31 - Math Course 1 (Book 1)

Multiplying Integers

Mo. 1

Lesson 5

KEY CONCEPTS:
1. Multiply Integers with the Same and Let’s Begin
Example A: 9 - 17 Example B: -7 - 3 Different Sign.
9 - 17 = 9 + (-17) -7 - 3 = -7 + (-3) 2. Simplify Algebraic Expressions.
= -8 = -10
Multiply Integers with
Different Signs
MO. 1 - L5a

Multiply Integers with the Examples

Same and Different Sign

Key Concept Find 8(–9)

8(–9) = –72 The factors have different signs.
Multiplying Integers with The product is negative.
Different Signs
Answer -72
Words: The product of two integers with
different signs is negative.
Find -9(11)
4 (-3) = -12
Examples: -9(11) = –99 The factors have different signs.
The product is negative.
-3 (4) = -12
Answer -99

Multiplying Integers with
the Same Signs
Multiply Integers with the
Words: The product of two integers with
the same signs is positive. Same Signs

Examples: 4 (3) = 12 Examples

3 (4) = 12 Find –4(–16)

-4(–16) = 64 The factors have same signs.
The product is positive.

Answer 64

Find –9(–3)(–2)
–9(–3)(–2) = [(–9)(–3)] (–2) Associative Property

= (27)(–2) (–9)(–3) = 27

= –54 (27)(–2) = –54

Answer -54

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