Problem 78
Question
Use the properties of logarithms to rewrite each expression as a single logarithm with coefficient 1. Assume that all variables represent positive real numbers. $$\left(\log _{b} k-\log _{b} m\right)-\log _{b} a$$
Step-by-Step Solution
Verified Answer
\( \log_b \left( \frac{k}{ma} \right) \)
1Step 1: Apply the Quotient Rule
The expression \( \log_b k - \log_b m \) can be rewritten using the quotient rule of logarithms. The quotient rule states that \( \log_b A - \log_b B = \log_b \left( \frac{A}{B} \right) \). By applying this rule: \( \log_b \left( \frac{k}{m} \right) \).
2Step 2: Introduce the Remaining Term
Now, incorporate the logarithm term \( -\log_b a \) into the expression from Step 1. This can be expressed as \( \log_b \left( \frac{k}{m} \right) - \log_b a \).
3Step 3: Reapply the Quotient Rule
With the subtraction form \( \log_b \left( \frac{k}{m} \right) - \log_b a \), apply the quotient rule again: \( \log_b \left( \frac{\frac{k}{m}}{a} \right) = \log_b \left( \frac{k}{ma} \right) \).
Key Concepts
Quotient RuleLogarithmic ExpressionsMathematical Transformations
Quotient Rule
The quotient rule is a key property in logarithms that simplifies expressions. It's like subtracting numbers, but with a focus on division. For logarithms, the rule says: \( \log_b A - \log_b B = \log_b \left( \frac{A}{B} \right) \). This means when you subtract two logarithms with the same base, it's the same as taking the logarithm of their division.
This rule helps us transform expressions, making them easier to handle. Think of it as combining two single-logarithm terms into one by using division. It's important because it paves the way for solving more complex logarithmic problems.
In these exercises, the quotient rule helps reduce multiple log terms into just one. This makes the calculation straightforward, mirroring simple arithmetic operations but in the logarithmic form.
This rule helps us transform expressions, making them easier to handle. Think of it as combining two single-logarithm terms into one by using division. It's important because it paves the way for solving more complex logarithmic problems.
In these exercises, the quotient rule helps reduce multiple log terms into just one. This makes the calculation straightforward, mirroring simple arithmetic operations but in the logarithmic form.
Logarithmic Expressions
Logarithmic expressions are combinations of numbers and variables within a logarithm. They transform complex mathematical operations into simpler ones. Think of logarithms as the reverse of exponentiation, giving power back to the base. Expressions like \( \log_b k - \log_b m \) involve the use of properties like the quotient rule to simplify.
Every logarithmic expression is unique, depending on the numbers or variables inside. By using properties such as the quotient and product rules, we convert multi-part expressions into single terms.
Simplifying logarithmic expressions is key in math because it allows for easier computation and understanding. For starters, always identify which rule or property applies before attempting to simplify. This turns what looks like a large problem into smaller, manageable pieces.
Every logarithmic expression is unique, depending on the numbers or variables inside. By using properties such as the quotient and product rules, we convert multi-part expressions into single terms.
Simplifying logarithmic expressions is key in math because it allows for easier computation and understanding. For starters, always identify which rule or property applies before attempting to simplify. This turns what looks like a large problem into smaller, manageable pieces.
Mathematical Transformations
Mathematical transformations include changing the form of an expression or equation using mathematical rules. In logarithms, transformations allow you to convert an expression into a more useful form. This includes altering the form of several logarithms into a single one.
Transformations use the properties of logarithms to adjust how an expression looks, without changing its value. For instance, using the quotient rule is a form of transformation. When transforming, you often make something complex look simpler to solve problems faster.
The benefit of these transformations is that they reveal the core relationship between numbers. A transformed expression is often easier to interpret, reconcile, or further simplify. This is especially useful in advanced math or real-world problem-solving where varied calculations are necessary.
Transformations use the properties of logarithms to adjust how an expression looks, without changing its value. For instance, using the quotient rule is a form of transformation. When transforming, you often make something complex look simpler to solve problems faster.
The benefit of these transformations is that they reveal the core relationship between numbers. A transformed expression is often easier to interpret, reconcile, or further simplify. This is especially useful in advanced math or real-world problem-solving where varied calculations are necessary.
Other exercises in this chapter
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