Page 63 - Math Course 2 (Book 1)

The Distributive Property

Mo. 2

Lesson 4 5(7 + 2) = 5 • 7 + 5 • 2 Distributive Property

= 35 + 10 Multiply.
KEY CONCEPTS: = 45 Add.
1. Use the Distributive Property to
evaluate expressions. Julia walks for 45 minutes each
2. Use the Distributive Property to Answer week.
simplify algebraic expressions.

The Distributive Property and
MO. 2 - L4a
Mental Math
Distributive Property: Example
Evaluate Expressions

Use the Distributive Property to f nd 12 • 82.
Key Concept 12 • 82 = 12(80 + 2) Think: 82 = 80 + 2

Distributive Property = 12(80) + 12(2) Distributive Property

= 960 + 24 Multiply.
Symbols
For any numbers a, b, and c, = 984 Add.
a (a + b) = ab + ac and (b + c) a= ba + ca and
a (a – b) = ab – ac and (b – c) a= ba –ca.
Answer 984
Examples
3 (2 + 5) = 3 • 2 + 3 • 5 4(9 – 7) = 4 • 9 – 4 • 7
3(7) = 6 + 15 4(2) = 36 – 38
21 = 21 8 = 8 Your Turn!

Distribute Over Addition or Subtraction

WALKING
Susanne walks to school and home from school 5
Let’s Begin days each week. She walks to school in 15 minutes
and then walks home in 10 minutes. Rewrite
5(15 + 10) using the Distributive Property.
Then evaluate to f nd the total number of minutes
Distribute Over Addition or Susanne spends walking to and home from school.
Subtraction A. 15 + 5 • 10; 65 minutes
B. 5 • 15 + 10; 85 minutes
Example C. 5 • 15 + 5 • 10; 125 minutes
D. 15 + 10; 25 minutes

EXERCISE Answer
Julia walks 5 days a week. She walks at a fast
rate for 7 minutes and then cools down for 2
minutes. Rewrite 5(7 + 2) using the Distributive
Property. Evaluate to f nd the total number of
minutes Julia walks.

55