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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
All textbooksLial 13th EditionCh. R - Review of Basic ConceptsProblem 77a
Chapter 1, Problem 77a

Simplify each complex fraction. [ 1/(a3+b3) ] / [ 1/(a2 + 2ab + b2) ]

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Identify the complex fraction: \(\frac{\frac{1}{a^3 + b^3}}{\frac{1}{a^2 + 2ab + b^2}}\).
Recall that dividing by a fraction is the same as multiplying by its reciprocal, so rewrite the expression as \(\frac{1}{a^3 + b^3} \times \frac{a^2 + 2ab + b^2}{1}\).
Recognize and factor the denominators where possible: factor \(a^3 + b^3\) using the sum of cubes formula \(a^3 + b^3 = (a + b)(a^2 - ab + b^2)\), and factor \(a^2 + 2ab + b^2\) as a perfect square trinomial \((a + b)^2\).
Substitute the factored forms back into the expression to get \(\frac{1}{(a + b)(a^2 - ab + b^2)} \times (a + b)^2\).
Simplify by canceling common factors: cancel one \((a + b)\) from numerator and denominator, leaving \(\frac{a + b}{a^2 - ab + b^2}\) as the simplified expression.

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Key Concepts

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

Complex Fractions

A complex fraction is a fraction where the numerator, denominator, or both are themselves fractions. Simplifying involves rewriting the expression as a division problem and then multiplying by the reciprocal of the denominator fraction to eliminate the complex fraction.
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Sum of Cubes Factorization

The sum of cubes formula states that a³ + b³ = (a + b)(a² - ab + b²). Recognizing and applying this factorization helps simplify expressions involving sums of cubes by breaking them into simpler polynomial factors.
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Factor by Grouping

Perfect Square Trinomials

A perfect square trinomial is an expression like a² + 2ab + b², which factors into (a + b)². Identifying this pattern allows for easier simplification and manipulation of algebraic expressions.
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Solving Quadratic Equations by Completing the Square
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