Skip to main content
Ch. P - Fundamental Concepts of Algebra
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 1, Problema 21

Multiply or divide as indicated. x3−8x2−4⋅x+23x\(\frac{x^3 - 8}{x^2 - 4}\) \(\cdot\) \(\frac{x + 2}{3x}\)

Guida verificata passo dopo passo
1
Identify the given expression to multiply: \(\frac{\left(x^3 - 8\right)}{\left(x^2 - 4\right)} \cdot \frac{\left(x + 2\right)}{3x}\).
Factor all polynomials where possible. Recognize that \(x^3 - 8\) is a difference of cubes and \(x^2 - 4\) is a difference of squares. Use the formulas: $a^3 - b^3 = (a - b)(a^2 + ab + b^2)$ and \(a^2 - b^2 = (a - b)(a + b)\).
Rewrite the expression with factored forms: \(\frac{(x - 2)(x^2 + 2x + 4)}{(x - 2)(x + 2)} \cdot \frac{(x + 2)}{3x}\).
Cancel out common factors in the numerator and denominator, such as \((x - 2)\) and \((x + 2)\), to simplify the expression.
Multiply the remaining factors in the numerator and denominator to write the simplified expression as a single fraction.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
2m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Polynomial Factoring

Factoring polynomials involves rewriting expressions as products of simpler polynomials. Recognizing special forms like difference of cubes (x³ - 8) and difference of squares (x² - 4) helps simplify expressions before multiplication or division.
Video consigliato:
07:30
Introduction to Factoring Polynomials

Multiplication and Division of Rational Expressions

When multiplying or dividing rational expressions, factor all numerators and denominators first, then multiply across numerators and denominators. For division, multiply by the reciprocal of the divisor to simplify the expression.
Video consigliato:
02:58
Rationalizing Denominators

Simplifying Rational Expressions

Simplifying involves canceling common factors in the numerator and denominator after factoring. This reduces the expression to its simplest form, making it easier to interpret or use in further calculations.
Video consigliato:
05:07
Simplifying Algebraic Expressions