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Ch. 4 - Exponential and Logarithmic Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 5, Problem 43

Use properties of logarithms to condense each logarithmic expression. Write the expression as a single logarithm whose coefficient is 1. Where possible, evaluate logarithmic expressions without using a calculator. ln x + ln 7

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Recall the logarithmic property that states the sum of logarithms with the same base can be written as the logarithm of the product: \(\ln a + \ln b = \ln(ab)\).
Identify the terms in the expression: \(\ln x + \ln 7\); here, \(a = x\) and \(b = 7\).
Apply the property by combining the two logarithms into one: \(\ln(x) + \ln(7) = \ln(x \times 7)\).
Simplify the product inside the logarithm: \(\ln(7x)\).
The expression is now condensed into a single logarithm with coefficient 1: \(\ln(7x)\).

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Key Concepts

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

Properties of Logarithms

Properties of logarithms include rules such as the product, quotient, and power rules. These allow combining or breaking down logarithmic expressions. For example, the product rule states that ln(a) + ln(b) = ln(ab), which helps condense sums of logarithms into a single logarithm.
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Natural Logarithm (ln)

The natural logarithm, denoted ln, is the logarithm with base e, where e ≈ 2.718. It is commonly used in calculus and algebra. Understanding ln is essential for manipulating expressions involving exponential growth or decay and applying logarithmic properties correctly.
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Condensing Logarithmic Expressions

Condensing logarithmic expressions means rewriting multiple logarithms as a single logarithm with a coefficient of 1. This involves applying logarithm properties to combine terms and simplify the expression, making it easier to evaluate or use in further calculations.
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