Table of contents

0. Review of Algebra4h 18m
1. Equations & Inequalities3h 18m
2. Graphs of Equations43m
3. Functions2h 17m
4. Polynomial Functions1h 44m
5. Rational Functions1h 23m
6. Exponential & Logarithmic Functions2h 28m
7. Systems of Equations & Matrices4h 6m
8. Conic Sections2h 23m
9. Sequences, Series, & Induction1h 22m
10. Combinatorics & Probability1h 45m

0. Review of Algebra

Factoring Polynomials

College Algebra

0. Review of Algebra

Factoring Polynomials

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1:49 minutes

Problem 47

Textbook Question

In Exercises 39–48, factor the difference of two squares. 16x^4−81

Verified step by step guidance

Recognize that the given expression, 16x^4 - 81, is a difference of two squares. Recall the formula for factoring the difference of two squares: a^2 - b^2 = (a - b)(a + b).

Rewrite each term as a square: 16x^4 can be written as (4x^2)^2, and 81 can be written as 9^2.

Substitute these squares into the formula: (4x^2)^2 - 9^2 = (4x^2 - 9)(4x^2 + 9).

Notice that the first factor, 4x^2 - 9, is itself a difference of two squares. Apply the formula again: 4x^2 - 9 = (2x - 3)(2x + 3).

Combine all the factors: The fully factored form of the expression is (2x - 3)(2x + 3)(4x^2 + 9).

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Key Concepts

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

Difference of Squares

The difference of squares is a specific algebraic expression that takes the form a^2 - b^2, which can be factored into (a - b)(a + b). This concept is fundamental in algebra as it simplifies expressions and solves equations efficiently. In the given problem, recognizing that 16x^4 and 81 are both perfect squares allows us to apply this factoring technique.

Perfect Squares

A perfect square is a number that can be expressed as the square of an integer or a variable. For example, 16x^4 is a perfect square because it can be written as (4x^2)^2, and 81 is a perfect square since it equals 9^2. Identifying perfect squares is crucial for factoring expressions involving the difference of squares.

Factoring Techniques

Factoring is the process of breaking down an expression into simpler components, or factors, that when multiplied together yield the original expression. Understanding various factoring techniques, including the difference of squares, is essential for solving polynomial equations and simplifying algebraic expressions. Mastery of these techniques enhances problem-solving skills in algebra.