Transcript over Lesson 3-2

WARM-UP PROBLEMS
(over Lesson 3-2)
Solve x + 31 = 53.
A. 12
B. 22
C. 74
D. 84
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(over Lesson 3-2)
Solve –5 + y = 13.
A. 18
B. 8
C. –8
D. –18
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(over Lesson 3-2)
Solve r – 7.2 = 22.8.
A. 3.2
B. 15.6
C. 30
D. 164
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Main Idea and Vocabulary
Key Concept: Division Property of Equality
Example 1: Solve Multiplication Equations
Example 2: Solve Multiplication Equations
• Solve multiplication equations (2.8.8E) (M7.D.2.1).
• Coefficient – the numerical factor for a
multiplication expression; EXAMPLE: the
coefficient of x in the expression 4x is 4.
• What is the relationship between
multiplication and division?
They are inverse operations.
• How is the relationship between
multiplication and division like the
relationship between addition and
subtraction?
They undo each other.
Give some examples to help explain your
reasoning.
How are addition and subtraction used to solve
equations? How might multiplication and
division be used to solve equations?
To solve addition equations, you subtract; To
solve subtraction equations, you add. So to solve
multiplication equations, you divide; to solve
division equations, you multiply.
What division facts are related to the
multiplication problem 3 x 4 = 12?
12  3 = 4; 12  4 = 3
BrainPOP:
Solving Equations
Solve Multiplication Equations
Solve 39 = 3y. Check your solution.
39 = 3y
Write the equation.
Divide each side of the equation by 3.
13 = y
39 ÷ 3 = 13
Answer: The solution is 13.
Check
39 =? 3y
13 = 3(13)
39 = 39 
Write the original equation.
Replace y with 13.
Solve 6m = 42. Check your solution.
A. 3
B. 7
C. 36
D. 48
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Solve Multiplication Equations
Solve –4z = 60. Check your solution.
–4z = 60
Write the equation.
Divide each side of the equation by –4.
z = 15
60 ÷ (–4) = –15
Answer: The solution is –15.
Check
–4z = 60 Write the original equation.
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–4(–15) = 60 Replace z with –15.
60 = 60 
Solve –64 = –16b. Check your solution.
A. –48
B. –4
C. 4
D. 80
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REVIEW
Solve each equation.
3
1. 6c = 18
5
2. 15 = 3z
3. -8x = 24 -3
4. -9r = -36 4
End of the Lesson
Five-Minute Check (over Lesson 3–2)
Image Bank
Math Tools
Solving Equations Using Models
Perimeter
Solving Equations
Two-Step Equations