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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 42

Find each root.81p12q44\(\sqrt\)[4]{81p^{12}q^4}

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1
Recognize that the expression involves a fourth root, which can be written as an exponent of \( \frac{1}{4} \). So, rewrite the expression \( \sqrt[4]{81p^{12}q^{4}} \) as \( (81p^{12}q^{4})^{\frac{1}{4}} \).
Apply the exponent \( \frac{1}{4} \) to each factor inside the parentheses separately: \( 81^{\frac{1}{4}} \), \( (p^{12})^{\frac{1}{4}} \), and \( (q^{4})^{\frac{1}{4}} \).
Simplify each term using the power of a power rule \( (a^{m})^{n} = a^{mn} \): \( 81^{\frac{1}{4}} \), \( p^{12 \times \frac{1}{4}} = p^{3} \), and \( q^{4 \times \frac{1}{4}} = q^{1} = q \).
Evaluate \( 81^{\frac{1}{4}} \) by recognizing that 81 is a perfect power of 3: \( 81 = 3^{4} \), so \( 81^{\frac{1}{4}} = 3 \).
Combine all simplified parts to write the final expression for the root as \( 3p^{3}q \).

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Key Concepts

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

Nth Root of a Number

The nth root of a number is a value that, when raised to the power n, equals the original number. For example, the fourth root (∜) of 81 is the number that raised to the 4th power gives 81. Understanding how to find roots is essential for simplifying expressions involving radicals.
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Properties of Exponents

Exponents indicate repeated multiplication, and their properties help simplify expressions. When taking roots, exponents can be divided by the root's index (e.g., the fourth root of p¹² is p^(12/4) = p³). This rule applies to variables and constants alike.
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Simplifying Radical Expressions

Simplifying radicals involves rewriting expressions to their simplest form by factoring and applying root and exponent rules. For example, breaking down 81 into 3⁴ helps find its fourth root easily. This process makes expressions easier to interpret and use.
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