Transcript Solving One-Step Multiplication Equations

Course 2
Solving Multiplication Equations
Objectives
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Review vocabulary
Review solving equations by adding or
subtracting
Solve multiplication equations using
Algebra tiles and paper and pencil
Solve practical problems
Review
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Use the following to answer the questions:
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6x + 5 – 3y = 12
Is it an equation, expression or an
Equation, it has an
inequality? How do you know? equals sign
Identify the term(s). 6x, 5, 3y and 12
Identify the variable(s). x and y
Identify the constant(s). 5 and 12
Identify the coefficient(s). 6 and -3
Review
Remember: Equations must be in balance,
like a scale.
 How would you solve this equation?
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x – 4 = 12
Use the opposite operation to undo the
subtraction.
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x – 4 + 4 = 12 + 4
x = 16
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Let’s look at how to solve an a
multiplication equation.
Division Property of Equality
 If
you divide each side of an
equation by the same nonzero
number, the two sides remain
equal.
Let’s Try It!
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1) 2x = -8
What is the coefficient in this
equation? 2
What is the opposite (inverse) of
multiplying by 2? Dividing by 2
2x = -8
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Use the division property of equality:
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Divide both sides of the equation by 2
 2x = -8
 2x = -8
2
2
x = -4
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2x = -8
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Check: 2x = -8
Replace the variable with the
solution:
 2(-4)
= -8
 -8 = -8
2) -5m = 40
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What is the coefficient in this equation? -5
What is the opposite (inverse) of
multiplying by -5? Dividing by -5
Divide both sides of the equation by -5?
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-5m = 40
-5m = 40
-5
-5
m = -8
-5m = 40
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Check -5m = 40
Replace the variable with the
solution:
 -5(-8) = 40
 40 = 40
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3) 30 = 6n
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What is the coefficient in this equation? 6
What is the opposite (inverse) of
multiplying by 6? Dividing by 6
Divide both sides of the equation by 6.
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30 = 6n
30 = 6n
6
6
5=n
30 = 6n
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Check 30 = 6n
Replace the variable with the
solution:
 30 = 6(5)
 30 = 30
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4) 1.2x = -4.8
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What is the coefficient in this equation? 1.2
What is the opposite (inverse) of
multiplying by 1.2? Dividing by 1.2
Divide both sides of the equation by 1.2.
 1.2x = -4.8
 1.2x = -4.8
1.2
1.2
x = -4
1.2x = -4.8
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Check 1.2x = -4.8
Replace the variable with the
solution:
 1.2(-4) = -4.8
 -4.8 = -4.8
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5) -3y = 2
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What is the coefficient in this equation? -3
What is the opposite (inverse) of multiplying by
-3? Dividing by -3
Divide both sides of the equation by -3.
 -3y = 2
 -3y = 2
-3
-3
2
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y= 3
-3y = 2
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Check -3y = 2
Replace the variable with the
solution:
2
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 -3( 3 ) = 2
 2 = 2
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Using an Equation to Solve a
Problem
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1) Sarah earns $5 per hour when she baby-sits.
How many hours does she need to work to earn
$75?
Write an equation:
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5h = 75
Solve the equation:
5h = 75
5
5
h = 15
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Sarah must work 15 hours to earn $75.00.
Using an Equation to Solve a
Problem.
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2) A 125 pound person uses 4.4 calories per
minute when walking. How many minutes will it
take this person to use 44 calories?
Write an equation:
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4.4m = 44
Solve the equation:
4.4m = 44
4.4
4.4
m = 10
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A 125 pound person must walk for 10 minutes to
use 44 calories.