Solve $2+5\ln{x}=21$: Find $x$

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SUMMARY

The equation $2 + 5\ln{x} = 21$ can be solved by isolating the logarithmic term, resulting in $\ln{x} = \frac{19}{5}$. This leads to the conclusion that $x = e^{\frac{19}{5}}$. The discussion emphasizes the understanding of exponents, which can take various forms including fractions and irrational numbers. Additionally, the forum participant is compiling a collection of precalculus problems for educational purposes, leveraging tools like OrangeDox for tracking engagement.

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  • Familiarity with exponential equations
  • Basic knowledge of algebraic manipulation
  • Experience with online collaborative tools like OrangeDox
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  • Explore the concept of exponential growth and decay
  • Learn how to use online tools for tracking educational resources
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karush
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$\tiny{6.1.07 kilana HS}$
Solve $2+5\ln{x}=21$
\$\begin{array}{rlll}
\textsf{isolate} &\ln{x} &=\dfrac{19}{5} &(1)\\
\textsf{then} & &= &(2)\\
\textsf{then} & &= &(3)\\
\textsf{hence} & &= &(4)
\end{array}$
ok for (2) I presume e thru then calculate for x
just strange to see a fraction as an e exponent
tryin array on these no sure if its better :unsure:
 
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[math]ln(x) = a \implies x = e^a[/math]

Does it make more sense if you think of it that way?

-Dan
 
You understand that an exponent is just a number, don't you? An exponent can be an integer, or a fraction, an irrational number, or a complex number.
 
roger
 
Country Boy said:
You understand that an exponent is just a number, don't you? An exponent can be an integer, or a fraction, an irrational number, or a complex number.
Or even a matrix... Buwahahahaha!

-Dan
 
https://dl.orangedox.com/QS7cBvdKw55RQUbliE

this is preliminary test to see if this works
but anyway I am trying to make a collection of 25 or more pre calc problems that came form students here on Oahu
I run a counter on the views and downloads, an earlier count it was over 50,000 on the MHB views
so it has been an awsome help. Hopefully more student from the island will join the forum when school starts up again
Im using OrangeDox because it keeps track of what happens with you posted files
 

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