Welcome to Westonci.ca, where your questions are met with accurate answers from a community of experts and enthusiasts. Discover a wealth of knowledge from professionals across various disciplines on our user-friendly Q&A platform. Explore comprehensive solutions to your questions from a wide range of professionals on our user-friendly platform.

Explain the error in the solution below. What additional step needs to be completed?

[tex]\[
\begin{aligned}
\log_5 x - \log_5 3 & = 2 \log_5 3 \\
\log_5 \left(\frac{x}{3}\right) & = 2 \log_5 3 \\
\log_5 \left(\frac{x}{3}\right) & = \log_5 3^2 \\
\frac{x}{3} & = 9 \\
x & = 27
\end{aligned}
\][/tex]

The error in the solution is in the first line. The correct step should be:
[tex]\[
\log_5 x - \log_5 3 = 2 \log_5 3 \quad \Rightarrow \quad \log_5 x - \log_5 3 = \log_5 3^2 \quad \Rightarrow \quad \log_5 x = \log_5 27
\][/tex]


Sagot :

The given solution has a misunderstanding due to the incorrect manipulation of logarithmic bases. Let's address each step and identify the mistake:

1. Starting Equation:
[tex]\[ \log x - \log_5 3 = 2 \log_5 3 \][/tex]
Here, [tex]\(\log\)[/tex] represents the common logarithm (base 10), and [tex]\(\log_5\)[/tex] represents the logarithm with base 5. This equation mixes different bases, which complicates direct manipulation.

2. Rewriting the Equation:
Before proceeding directly to solve the equation, let's rewrite it with common bases.

We use the change of base formula [tex]\(\log_5 x = \frac{\log x}{\log 5}\)[/tex] to convert [tex]\(\log_5 3\)[/tex] to base 10 logarithms:
[tex]\[ \log_5 3 = \frac{\log 3}{\log 5} \][/tex]

3. Substituting into the Equation:
Substituting [tex]\(\log_5 3\)[/tex] into the original equation, we get:
[tex]\[ \log x - \frac{\log 3}{\log 5} = 2 \cdot \frac{\log 3}{\log 5} \][/tex]

4. Combining Terms:
To combine terms on the left side:
[tex]\[ \log x = \frac{\log 3}{\log 5} + 2 \cdot \frac{\log 3}{\log 5} \][/tex]
Simplifying the right-hand side:
[tex]\[ \log x = \frac{\log 3}{\log 5} + \frac{2 \log 3}{\log 5} \][/tex]
[tex]\[ \log x = \frac{\log 3 + 2 \log 3}{\log 5} \][/tex]
[tex]\[ \log x = \frac{3 \log 3}{\log 5} \][/tex]

5. Solving for [tex]\(x\)[/tex]:
Converting [tex]\(\log x\)[/tex] from logarithmic form to exponential form:
[tex]\[ x = 10^{\frac{3 \log 3}{\log 5}} \][/tex]

6. Evaluating the Exponent:
The exponent can be simplified to the form:
[tex]\[ 3 \cdot \log_5 3 \][/tex]

To find [tex]\( x \)[/tex], we need to evaluate this using the base 10 logarithms:
[tex]\[ x \approx 111.63968012488048 \][/tex]

So, the corrected solution yields the answer [tex]\( x \approx 111.63968012488048 \)[/tex]. The previous error was the oversight in handling the mixed logarithmic bases.
Thank you for your visit. We're dedicated to helping you find the information you need, whenever you need it. Thanks for stopping by. We strive to provide the best answers for all your questions. See you again soon. Find reliable answers at Westonci.ca. Visit us again for the latest updates and expert advice.