Skip to main content
Ch. 5 - Systems of Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 6, Problem 16

In Exercises 16–24, write the partial fraction decomposition of each rational expression. x/(x - 3)(x + 2)

Verified step by step guidance
1
Step 1: Recognize that the given rational expression \( \frac{x}{(x - 3)(x + 2)} \) is a proper fraction because the degree of the numerator (1) is less than the degree of the denominator (2). This means we can proceed with partial fraction decomposition.
Step 2: Set up the partial fraction decomposition. Since the denominator \((x - 3)(x + 2)\) consists of two distinct linear factors, the decomposition will take the form: \( \frac{x}{(x - 3)(x + 2)} = \frac{A}{x - 3} + \frac{B}{x + 2} \), where \(A\) and \(B\) are constants to be determined.
Step 3: Multiply through by the common denominator \((x - 3)(x + 2)\) to eliminate the fractions. This gives: \( x = A(x + 2) + B(x - 3) \).
Step 4: Expand and simplify the right-hand side. Distribute \(A\) and \(B\) to get: \( x = A \cdot x + 2A + B \cdot x - 3B \). Combine like terms: \( x = (A + B)x + (2A - 3B) \).
Step 5: Equate coefficients of like terms from both sides of the equation. For the \(x\)-terms: \( A + B = 1 \). For the constant terms: \( 2A - 3B = 0 \). Solve this system of linear equations to find \(A\) and \(B\). Substitute these values back into the partial fraction decomposition.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
6m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Rational Expressions

A rational expression is a fraction where both the numerator and the denominator are polynomials. Understanding rational expressions is crucial for performing operations such as addition, subtraction, multiplication, and division, as well as for decomposing them into simpler components, which is the focus of this question.
Recommended video:
Guided course
02:58
Rationalizing Denominators

Partial Fraction Decomposition

Partial fraction decomposition is a method used to express a rational function as a sum of simpler fractions. This technique is particularly useful for integrating rational expressions or simplifying complex algebraic fractions, allowing for easier manipulation and analysis of the expression.
Recommended video:
4:07
Decomposition of Functions

Factoring Polynomials

Factoring polynomials involves breaking down a polynomial into its constituent factors, which can be linear or irreducible quadratic expressions. This process is essential for identifying the structure of the denominator in a rational expression, as it helps determine the form of the partial fractions needed for decomposition.
Recommended video:
Guided course
07:30
Introduction to Factoring Polynomials