Canceling Common Factors Again

Oct 13, 2025 by wbrum.org 63 views

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Introduction

In this article, we will be discussing the process of dividing two algebraic expressions, specifically a fraction divided by another fraction. We will be using the given problem $\frac{x^2-2x-15}{x+2} \div \frac{x^2-x-12}{x+2}$ to demonstrate the steps involved in simplifying the quotient.

Understanding the Problem

The given problem involves dividing two fractions, which can be rewritten as multiplying the first fraction by the reciprocal of the second fraction. This can be represented as:

\frac{x^2-2x-15}{x+2} \div \frac{x^2-x-12}{x+2} = \frac{x^2-2x-15}{x+2} \cdot \frac{x+2}{x^2-x-12}

Simplifying the Quotient

To simplify the quotient, we need to multiply the numerators and denominators of the two fractions. This can be represented as:

\frac{(x^2-2x-15)(x+2)}{(x+2)(x^2-x-12)}

Canceling Common Factors

We can see that the factor $(x+2)$ is present in both the numerator and denominator. Therefore, we can cancel out this common factor to simplify the expression:

\frac{(x^2-2x-15)(x+2)}{(x+2)(x^2-x-12)} = \frac{x^2-2x-15}{x^2-x-12}

Further Simplification

We can further simplify the expression by factoring the numerator and denominator. The numerator can be factored as:

x^2-2x-15 = (x-5)(x+3)

The denominator can be factored as:

x^2-x-12 = (x-4)(x+3)

Canceling Common Factors Again

We can see that the factor $(x+3)$ is present in both the numerator and denominator. Therefore, we can cancel out this common factor to simplify the expression:

\frac{(x-5)(x+3)}{(x-4)(x+3)} = \frac{x-5}{x-4}

Conclusion

In conclusion, the quotient of the given problem $\frac{x^2-2x-15}{x+2} \div \frac{x^2-x-12}{x+2}$ can be simplified to $\frac{x-5}{x-4}$ .

Final Answer

The final answer is $\boxed{\frac{x-5}{x-4}}$ .

Discussion

This problem involves the concept of dividing fractions, which is a fundamental concept in algebra. The process of simplifying the quotient involves canceling common factors and factoring the numerator and denominator. This problem requires the student to have a good understanding of algebraic expressions and the concept of division.

Practice Problems

Here are some practice problems to help reinforce the concept of dividing fractions:

$\frac{x^2+4x+3}{x+1} \div \frac{x^2+2x+1}{x+1}$
$\frac{x^2-5x-6}{x-1} \div \frac{x^2-3x-2}{x-1}$
$\frac{x^2+2x+1}{x+1} \div \frac{x^2+4x+3}{x+1}$

Solutions

Here are the solutions to the practice problems:

$\frac{x^2+4x+3}{x+1} \div \frac{x^2+2x+1}{x+1} = \frac{x^2+4x+3}{x^2+2x+1} = \frac{(x+1)(x+3)}{(x+1)(x+1)} = \frac{x+3}{x+1}$
$\frac{x^2-5x-6}{x-1} \div \frac{x^2-3x-2}{x-1} = \frac{x^2-5x-6}{x^2-3x-2} = \frac{(x-1)(x-6)}{(x-1)(x+2)} = \frac{x-6}{x+2}$
$\frac{x^2+2x+1}{x+1} \div \frac{x^2+4x+3}{x+1} = \frac{x^2+2x+1}{x^2+4x+3} = \frac{(x+1)(x+1)}{(x+1)(x+3)} = \frac{x+1}{x+3}$

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Q: What is the concept of dividing fractions?

A: Dividing fractions is a mathematical operation that involves dividing one fraction by another fraction. It is a fundamental concept in algebra and is used to simplify complex expressions.

Q: How do I divide fractions?

A: To divide fractions, you need to multiply the first fraction by the reciprocal of the second fraction. This can be represented as:

\frac{a}{b} \div \frac{c}{d} = \frac{a}{b} \cdot \frac{d}{c}

Q: What is the reciprocal of a fraction?

A: The reciprocal of a fraction is obtained by swapping the numerator and denominator. For example, the reciprocal of $\frac{a}{b}$ is $\frac{b}{a}$ .

Q: How do I simplify a quotient of fractions?

A: To simplify a quotient of fractions, you need to cancel out any common factors between the numerator and denominator. This can be done by factoring the numerator and denominator and canceling out any common factors.

Q: What are some common mistakes to avoid when dividing fractions?

A: Some common mistakes to avoid when dividing fractions include:

Not canceling out common factors between the numerator and denominator
Not using the reciprocal of the second fraction
Not simplifying the quotient

Q: How do I know if a fraction is in its simplest form?

A: A fraction is in its simplest form if there are no common factors between the numerator and denominator. You can check if a fraction is in its simplest form by factoring the numerator and denominator and canceling out any common factors.

Q: What are some real-world applications of dividing fractions?

A: Dividing fractions has many real-world applications, including:

Cooking: When measuring ingredients, you may need to divide fractions to get the correct amount.
Science: In scientific experiments, you may need to divide fractions to calculate the results.
Finance: In finance, you may need to divide fractions to calculate interest rates or investment returns.

Q: How do I practice dividing fractions?

A: You can practice dividing fractions by working through examples and exercises. You can also use online resources or math software to practice dividing fractions.

Q: What are some common types of division problems involving fractions?

A: Some common types of division problems involving fractions include:

Dividing fractions with like denominators
Dividing fractions with unlike denominators
Simplifying complex fractions
Canceling common factors in fractions

Q: How do I know if a division problem involving fractions is correct?

A: To check if a division problem involving fractions is correct, you can:

Simplify the quotient and check if it is in its simplest form
Check if the numerator and denominator have any common factors
Use a calculator or online resource to check the answer

Q: What are some tips for mastering dividing fractions?

A: Some tips for mastering dividing fractions include:

Practicing regularly to build confidence and skills
Using visual aids such as diagrams or charts to help understand the concept
Breaking down complex problems into simpler steps
Checking your work to ensure accuracy

Q: How do I apply dividing fractions to real-world problems?

A: To apply dividing fractions to real-world problems, you can:

Identify the problem and determine the type of division problem it is
Use the concept of dividing fractions to solve the problem
Check your work to ensure accuracy
Communicate the solution clearly and effectively

Q: What are some common mistakes to avoid when applying dividing fractions to real-world problems?

A: Some common mistakes to avoid when applying dividing fractions to real-world problems include:

Not identifying the type of division problem
Not using the concept of dividing fractions correctly
Not checking your work for accuracy
Not communicating the solution clearly and effectively