Select the correct answer.

What is the approximate solution to this equation?

[tex]\[ 4 \ln x - 8 = 12 \][/tex]

A. [tex]\[ x \approx 10.5 \][/tex]

B. [tex]\[ x \approx 1.61 \][/tex]

C. [tex]\[ x \approx 59,874 \][/tex]

D. [tex]\[ x \approx 148.4 \][/tex]



Answer :

To solve the equation [tex]\(4 \ln x - 8 = 12\)[/tex], follow these steps:

1. Isolate the logarithmic term:
[tex]\[ 4 \ln x - 8 = 12 \][/tex]
Add 8 to both sides to isolate the logarithmic expression:
[tex]\[ 4 \ln x = 20 \][/tex]

2. Divide by 4 to solve for [tex]\(\ln x\)[/tex]:
[tex]\[ \ln x = \frac{20}{4} \][/tex]
[tex]\[ \ln x = 5 \][/tex]

3. Exponentiate both sides to solve for [tex]\(x\)[/tex]:
The natural logarithm function [tex]\(\ln\)[/tex] is the inverse of the exponential function with base [tex]\(e\)[/tex]. Therefore, to undo the logarithm, exponentiate both sides with base [tex]\(e\)[/tex]:
[tex]\[ x = e^5 \][/tex]

4. Compute the numerical value:
Using a calculator or a tables of exponents, we find:
[tex]\[ e^5 \approx 148.413159 \][/tex]

Thus, the approximate value of [tex]\(x\)[/tex] is 148.413159. Comparing this to the given choices, the closest approximation is [tex]\(x \approx 148.4\)[/tex].

Therefore, the correct answer is:
[tex]\[ \boxed{x \approx 148.4} \][/tex]