12.2.1 - Method of common factors
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Introduction to Common Factors
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Today, we're going to explore how to factorize expressions using common factors. Can anyone tell me what a factor is?
A factor is a number or expression that can be multiplied to get another number or expression.
Great! So, when we talk about common factors, we mean factors that are shared by different terms in an expression. For instance, in the expression 2x + 4, can someone show me how we can break that down?
We can write 2x as 2 times x, and 4 as 2 times 2.
Exactly! So we notice that 2 is a common factor. By factorizing, we can write it as 2(x + 2). This makes simplifying expressions easier. Who can summarize why we do this?
We factor expressions to find their simplest form and understand their components better.
Well done! Now let’s look at another example to solidify our understanding.
Working with More Complex Expressions
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Let’s factor 5xy + 10x. What do we notice here?
Both terms seem to have 5 and x as common factors!
Excellent! So how can we express that?
We can write it as 5x(y + 2).
Correct! Remember, identifying common factors not only helps to simplify but also to solve equations quicker. Can we think of another similar expression to practice?
How about 12a^2b + 15ab^2?
Great choice! Let’s factor this expression together.
Exploring Factorization through Grouping
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In some cases, like 2xy + 2y + 3x + 3, we might have to group terms strategically. Why do you think that is?
Because not all terms have a direct common factor, but we can pair them to find one.
Exactly! Let's take the first two terms and the last two. What can we factor out from each group?
From the first group, we can factor out 2y, and from the second, we can factor out 3.
Then we can express it as 2y(x + 1) + 3(x + 1). Now that we have a common factor across the two groups, what can we do next?
We can factor out (x + 1) to get our final expression as (x + 1)(2y + 3).
Excellent work everyone! Let's summarize this process of grouping and factorization.
Introduction to Common Factors
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Today, we're going to explore how to factorize expressions using common factors. Can anyone tell me what a factor is?
A factor is a number or expression that can be multiplied to get another number or expression.
Great! So, when we talk about common factors, we mean factors that are shared by different terms in an expression. For instance, in the expression 2x + 4, can someone show me how we can break that down?
We can write 2x as 2 times x, and 4 as 2 times 2.
Exactly! So we notice that 2 is a common factor. By factorizing, we can write it as 2(x + 2). This makes simplifying expressions easier. Who can summarize why we do this?
We factor expressions to find their simplest form and understand their components better.
Well done! Now let’s look at another example to solidify our understanding.
Working with More Complex Expressions
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Let’s factor 5xy + 10x. What do we notice here?
Both terms seem to have 5 and x as common factors!
Excellent! So how can we express that?
We can write it as 5x(y + 2).
Correct! Remember, identifying common factors not only helps to simplify but also to solve equations quicker. Can we think of another similar expression to practice?
How about 12a^2b + 15ab^2?
Great choice! Let’s factor this expression together.
Exploring Factorization through Grouping
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Sign up and enroll to listen to this audio lesson
In some cases, like 2xy + 2y + 3x + 3, we might have to group terms strategically. Why do you think that is?
Because not all terms have a direct common factor, but we can pair them to find one.
Exactly! Let's take the first two terms and the last two. What can we factor out from each group?
From the first group, we can factor out 2y, and from the second, we can factor out 3.
Then we can express it as 2y(x + 1) + 3(x + 1). Now that we have a common factor across the two groups, what can we do next?
We can factor out (x + 1) to get our final expression as (x + 1)(2y + 3).
Excellent work everyone! Let's summarize this process of grouping and factorization.
Introduction & Overview
Read summaries of the section's main ideas at different levels of detail.
Quick Overview
Standard
The method of common factors involves rewriting algebraic expressions as products of their irreducible factors by identifying shared factors in different terms. The process is outlined through examples, illustrating how to group terms, factor them out, and arrive at a simplified form.
Detailed
Method of Common Factors
In this section, we explore the method of common factors, a key technique in algebraic factorization. The process begins by expressing algebraic expressions as sums of terms that can be grouped based on their common factors. This method follows a systematic approach:
1. Identify Common Factors: Each term of the expression is represented as a product of its irreducible factors.
2. Group Terms: Terms with shared factors are grouped together.
3. Factor Out the Common Elements: Using distributive properties, we can extract the common factors, leading to a simplified expression.
Example: To factorize the expression 2x + 4, we first identify both terms can be expressed with the factor 2:
- 2x = 2 × x
- 4 = 2 × 2
Thus, rewriting yields:
2x + 4 = 2(x + 2).
The common factor method enhances understanding of algebra by simplifying expressions and lays the foundation for exploring more complex factorization techniques later in the chapter.
Youtube Videos
Key Concepts
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Identifying Common Factors: Recognizing factors shared among terms is crucial for simplifying expressions.
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Method of Grouping: This technique involves rearranging and grouping terms strategically for effective factorization.
Examples & Applications
Example: Factor 2x + 4 - By observing 2 is common, we rewrite as 2(x + 2).
Example: Factor 5xy + 10x - Recognizing both have factors 5 and x leading to 5x(y + 2).
Memory Aids
Interactive tools to help you remember key concepts
Rhymes
To factorize we must detect, the common factor to select.
Stories
Once upon a time, in a land of numbers, 12 and 36 were searching for their common friend, the biggest number they could share.
Memory Tools
FIND: First Identify Number that Divides.
Acronyms
C-Factor
Common-Factor to Factorize.
Flash Cards
Glossary
- Common Factor
A factor that is shared among different terms in an expression.
- Irreducible Factor
A factor that cannot be further broken down into simpler components.
- Factorization
The process of breaking down an expression into a product of its factors.
- Distributive Law
A mathematical property allowing the multiplication of a single term across terms in parentheses.
Reference links
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