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Ch. R - Review of Basic Concepts
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 1, Problem 90

Factor each polynomial. See Example 7. (5x-2)3-8

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Recognize that the expression \( (5x - 2)^3 - 8 \) is a difference of cubes, since \(8\) can be written as \$2^3$.
Recall the difference of cubes formula: \(a^3 - b^3 = (a - b)(a^2 + ab + b^2)\).
Identify \(a = (5x - 2)\) and \(b = 2\) in the expression.
Apply the formula: write the factorization as \(((5x - 2) - 2)((5x - 2)^2 + (5x - 2)(2) + 2^2)\).
Simplify each factor: first simplify \(((5x - 2) - 2)\), then expand and simplify the quadratic expression inside the second factor.

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Key Concepts

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

Difference of Cubes

The difference of cubes formula states that a³ - b³ = (a - b)(a² + ab + b²). It is used to factor expressions where two perfect cubes are subtracted. Recognizing the structure helps simplify polynomials like (5x - 2)³ - 8 by identifying a = (5x - 2) and b = 2.
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Polynomial Factoring

Polynomial factoring involves rewriting a polynomial as a product of simpler polynomials. This process simplifies expressions and solves equations. Factoring techniques include recognizing special products like difference of squares, sum/difference of cubes, and factoring by grouping.
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Exponents and Powers

Understanding exponents is crucial for identifying perfect cubes and manipulating expressions like (5x - 2)³. Exponents indicate repeated multiplication, and recognizing powers helps in applying formulas such as the difference of cubes for factoring.
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