Skip to main content
Ch. 3 - Polynomial and Rational Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 4, Problem 75

When 2x2−7x+9 is divided by a polynomial, the quotient is 2x-3 and the remainder is 3. Find the polynomial.

Verified step by step guidance
1
Recall the polynomial division identity: Dividend = (Divisor) × (Quotient) + Remainder.
Let the divisor polynomial be denoted as \(D(x)\). According to the problem, the dividend is \(2x^{2} - 7x + 9\), the quotient is \(2x - 3\), and the remainder is 3.
Set up the equation: \(2x^{2} - 7x + 9 = D(x) \times (2x - 3) + 3\).
Rearrange the equation to isolate \(D(x)\): \(D(x) = \frac{2x^{2} - 7x + 9 - 3}{2x - 3} = \frac{2x^{2} - 7x + 6}{2x - 3}\).
Perform polynomial division or factorization on the numerator \(2x^{2} - 7x + 6\) to simplify the expression and find \(D(x)\).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4m
Was this helpful?

Key Concepts

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

Polynomial Division

Polynomial division involves dividing one polynomial by another, resulting in a quotient and a remainder. The dividend equals the divisor multiplied by the quotient plus the remainder. Understanding this relationship is essential to reconstruct the divisor when the dividend, quotient, and remainder are known.
Recommended video:
Guided course
05:13
Introduction to Polynomials

Forming Equations from Polynomial Expressions

Given the dividend, quotient, and remainder, you can set up an equation: Dividend = Divisor × Quotient + Remainder. This equation allows you to solve for the unknown polynomial divisor by expressing it in terms of the known polynomials and constants.
Recommended video:
Guided course
05:16
Standard Form of Polynomials

Solving for Unknown Polynomials

To find the unknown polynomial divisor, rearrange the equation and perform algebraic operations such as polynomial subtraction and division. Matching coefficients of corresponding powers of x helps determine the coefficients of the unknown polynomial.
Recommended video:
05:01
Identifying Intervals of Unknown Behavior