Question 5 (Multiple Choice Worth 2 points)

Solve [tex]\(4^{x+2}=12\)[/tex] for [tex]\(x\)[/tex] using the change of base formula [tex]\(\log_b y = \frac{\log y}{\log b}\)[/tex].

A. [tex]\(-1.442114\)[/tex]

B. [tex]\(-0.207519\)[/tex]

C. [tex]\(2.55789\)[/tex]

D. [tex]\(379248\)[/tex]



Answer :

To solve the equation [tex]\(4^{x+2}=12\)[/tex] for [tex]\(x\)[/tex] using the change of base formula [tex]\(\log_b y = \frac{\log y}{\log b}\)[/tex], follow these steps:

1. Apply the natural logarithm to both sides of the equation:

[tex]\[ \ln(4^{(x+2)}) = \ln(12) \][/tex]

2. Use the power rule for logarithms, which states [tex]\(\ln(a^b) = b \ln(a)\)[/tex]:

[tex]\[ (x+2) \ln(4) = \ln(12) \][/tex]

3. Solve for [tex]\(x + 2\)[/tex]:

[tex]\[ x + 2 = \frac{\ln(12)}{\ln(4)} \][/tex]

4. Calculate the numerical value:

[tex]\[ x + 2 \approx \frac{2.4849066497880004}{1.3862943611198906} \approx 1.7924812503605783 \][/tex]

5. Isolate [tex]\(x\)[/tex] by subtracting 2 from both sides:

[tex]\[ x = 1.7924812503605783 - 2 \approx -0.20751874963942174 \][/tex]

Hence, the solution to the equation [tex]\(4^{x+2} = 12\)[/tex] for [tex]\(x\)[/tex] is approximately [tex]\(-0.207519\)[/tex].

Thus, the correct multiple-choice answer is:
[tex]\[ -0.207519 \][/tex]