Chapter 1: Problem 58
Factor the polynomial. $$ 12 x^{2}-x-6 $$
Short Answer
Expert verified
The factored form is \((4x - 3)(3x + 2)\).
Step by step solution
01
Identify Coefficients
The given polynomial is \( 12x^2 - x - 6 \). Identify the coefficients: \( a = 12 \), \( b = -1 \), and \( c = -6 \).
02
Multiply 'a' and 'c'
Multiply the coefficient of \( x^2 \) (\( a = 12 \)) by the constant term (\( c = -6 \)): \( 12 imes -6 = -72 \).
03
Find Two Numbers
Find two numbers that multiply to \(-72\) and add to the middle coefficient \(-1\). The numbers are \(8\) and \(-9\).
04
Rewrite the Middle Term
Rewrite the polynomial by splitting the \(-x\) term into \(8x - 9x\): \( 12x^2 + 8x - 9x - 6 \).
05
Factor by Grouping
Group the terms: \((12x^2 + 8x) + (-9x - 6)\). Factor each group: \(4x(3x + 2) - 3(3x + 2)\).
06
Factor Out Common Binomial
Notice that \(3x + 2\) is common in both groups, factor it out: \((4x - 3)(3x + 2)\).
07
Verify the Factored Form
To ensure the factorization is correct, expand \((4x - 3)(3x + 2)\) and verify it equals the original polynomial: \(12x^2 + 8x - 9x - 6 = 12x^2 - x - 6\).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Quadratic Polynomials
Quadratic polynomials are a type of polynomial that are extremely common in algebra. They take the general form: \( ax^2 + bx + c \), where \( a \), \( b \), and \( c \) are constants.
Here is what each part means:
In our example, the quadratic polynomial is \( 12x^2 - x - 6 \), where \( a = 12 \), \( b = -1 \), and \( c = -6 \). The goal is to factor this expression into a product of simpler polynomials.
Here is what each part means:
- \( a \) is the coefficient of the quadratic term \( x^2 \).
- \( b \) is the coefficient of the linear term \( x \).
- \( c \) is the constant term with no variable attached.
In our example, the quadratic polynomial is \( 12x^2 - x - 6 \), where \( a = 12 \), \( b = -1 \), and \( c = -6 \). The goal is to factor this expression into a product of simpler polynomials.
Factoring by Grouping
Factoring by grouping is a method used to factor certain polynomial expressions. It involves rearranging the terms of a polynomial and grouping them in pairs in such a way that each pair can be factored separately.
Here's a step-by-step breakdown of how it works:
Here's a step-by-step breakdown of how it works:
- First, identify any common factors in the groups of terms. These groups are usually selected so that a common factor exists.
- Then, factor out the common factor from each group.
- Finally, if there is a common binomial factor between the two groups, factor it out of the expression.
Polynomial Coefficients
Polynomial coefficients are the numbers that multiply the variable terms in a polynomial. They are crucial in determining the characteristics and behavior of the polynomial.
Let's explore this concept further:
Let's explore this concept further:
- The leading coefficient is the number in front of the highest degree term, determining the polynomial's global shape.
- The constant term, or the term with no variable factor, provides the polynomial's value when all variables are zero.
- Intermediate coefficients affect the polynomial's direction and symmetry.
- The leading coefficient \( a \) is 12, indicating that as \( x \) becomes very large or very small, \( \pm12x^2 \) will dominate the polynomial's behavior.
- The linear coefficient \( b \) is -1, influencing the slope of the parabola represented by the polynomial when graphing.
- The constant term \( c \) is -6, which is the value of the polynomial when \( x = 0 \).