Factoring by synthetic division

Oct 13, 2025 by wbrum.org 65 views

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Introduction

Factoring polynomials is a fundamental concept in algebra that involves expressing a polynomial as a product of simpler polynomials. In this article, we will explore the process of factoring polynomials, with a focus on prime polynomials. We will also provide a step-by-step solution to a problem that requires factoring a given polynomial.

What are Prime Polynomials?

A prime polynomial is a polynomial that cannot be factored into the product of two or more polynomials with integer coefficients. In other words, a prime polynomial is a polynomial that is irreducible over the integers. For example, the polynomial $x^2 + 1$ is a prime polynomial because it cannot be factored into the product of two polynomials with integer coefficients.

How to Factor Polynomials

Factoring polynomials involves expressing a polynomial as a product of simpler polynomials. There are several methods for factoring polynomials, including:

Factoring out the greatest common factor (GCF): This involves factoring out the largest polynomial that divides each term of the polynomial.
Factoring by grouping: This involves grouping the terms of the polynomial into pairs and factoring out the GCF of each pair.
Factoring quadratics: This involves factoring quadratic polynomials of the form $ax^2 + bx + c$ .
Factoring by synthetic division: This involves using synthetic division to factor polynomials.

Step-by-Step Solution to the Problem

The problem requires us to factor the polynomial $36x^3 - 15x^2 - 6x$ . To solve this problem, we will use the method of factoring out the GCF.

Step 1: Factor out the GCF

The first step in factoring the polynomial is to factor out the GCF. In this case, the GCF is $3x$ . Factoring out $3x$ from each term of the polynomial, we get:

36x^3 - 15x^2 - 6x = 3x(12x^2 - 5x - 2)

Step 2: Factor the Quadratic

The next step is to factor the quadratic polynomial $12x^2 - 5x - 2$ . To do this, we can use the quadratic formula or complete the square. In this case, we will use the quadratic formula.

The quadratic formula is given by:

x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

In this case, $a = 12$ , $b = -5$ , and $c = -2$ . Plugging these values into the quadratic formula, we get:

x = \frac{-(-5) \pm \sqrt{(-5)^2 - 4(12)(-2)}}{2(12)}

Simplifying this expression, we get:

x = \frac{5 \pm \sqrt{25 + 96}}{24}

x = \frac{5 \pm \sqrt{121}}{24}

x = \frac{5 \pm 11}{24}

Therefore, the solutions to the quadratic equation are:

x = \frac{5 + 11}{24} = \frac{16}{24} = \frac{2}{3}

x = \frac{5 - 11}{24} = \frac{-6}{24} = -\frac{1}{4}

Step 3: Write the Factored Form

Now that we have factored the quadratic polynomial, we can write the factored form of the original polynomial. The factored form is given by:

36x^3 - 15x^2 - 6x = 3x(3x - 2)(4x + 1)

Conclusion

In this article, we have explored the process of factoring polynomials, with a focus on prime polynomials. We have also provided a step-by-step solution to a problem that requires factoring a given polynomial. The solution involves factoring out the GCF, factoring the quadratic polynomial, and writing the factored form of the original polynomial.

Answer to the Problem

The correct answer to the problem is:

A. $x(3x - 2)(4x + 1)$

This is because the factored form of the polynomial $36x^3 - 15x^2 - 6x$ is $3x(3x - 2)(4x + 1)$ .

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Introduction

In our previous article, we explored the process of factoring polynomials, with a focus on prime polynomials. We also provided a step-by-step solution to a problem that requires factoring a given polynomial. In this article, we will answer some of the most frequently asked questions about factoring polynomials.

Q&A

Q: What is the difference between factoring and simplifying a polynomial?

A: Factoring a polynomial involves expressing it as a product of simpler polynomials, while simplifying a polynomial involves combining like terms to reduce the polynomial to its simplest form.

Q: How do I know if a polynomial can be factored?

A: A polynomial can be factored if it can be expressed as a product of simpler polynomials. To determine if a polynomial can be factored, try to identify any common factors among the terms.

Q: What is the greatest common factor (GCF) of a polynomial?

A: The GCF of a polynomial is the largest polynomial that divides each term of the polynomial. Factoring out the GCF is a common technique used to simplify polynomials.

Q: How do I factor a quadratic polynomial?

A: To factor a quadratic polynomial, try to identify two numbers whose product is equal to the constant term and whose sum is equal to the coefficient of the linear term. These two numbers are the roots of the quadratic equation.

Q: What is synthetic division?

A: Synthetic division is a technique used to divide a polynomial by a linear factor. It involves using a table to divide the polynomial and find the quotient and remainder.

Q: How do I use synthetic division to factor a polynomial?

A: To use synthetic division to factor a polynomial, first identify the linear factor that you want to divide the polynomial by. Then, use synthetic division to divide the polynomial and find the quotient and remainder. The quotient is the other factor of the polynomial.

Q: What is the difference between factoring and solving a polynomial equation?

A: Factoring a polynomial equation involves expressing it as a product of simpler polynomials, while solving a polynomial equation involves finding the values of the variable that make the equation true.

Q: How do I solve a polynomial equation?

A: To solve a polynomial equation, try to factor the equation and set each factor equal to zero. Then, solve for the variable.

Conclusion

In this article, we have answered some of the most frequently asked questions about factoring polynomials. We hope that this article has provided you with a better understanding of the process of factoring polynomials and how to use it to solve polynomial equations.

Additional Resources

For more information on factoring polynomials, check out the following resources:

Mathway: A online math problem solver that can help you with factoring polynomials and other math problems.
Khan Academy: A free online resource that provides video lessons and practice exercises on factoring polynomials and other math topics.
Wolfram Alpha: A online calculator that can help you with factoring polynomials and other math problems.

Final Thoughts

Factoring polynomials is an important concept in algebra that can be used to solve polynomial equations and simplify polynomials. By understanding how to factor polynomials, you can solve a wide range of math problems and become a more confident and proficient math student.