- Combine the logarithmic terms on one side of the equation.
- Use properties of logarithms to simplify the equation.
- Solve for \(x\).
First, we need to isolate the logarithmic terms. Let's move all the logarithmic terms to one side of the equation:
\[
4 + \log(8x) + 2\log(x) = 25
\]
Next, we use the properties of logarithms to combine the terms:
\[
4 + \log(8x) + \log(x^2) = 25
\]
\[
4 + \log(8x \cdot x^2) = 25
\]
\[
4 + \log(8x^3) = 25
\]
Subtract 4 from both sides:
\[
\log(8x^3) = 21
\]
Rewrite the logarithmic equation in exponential form:
\[
8x^3 = 10^{21}
\]
Solve for \(x\):
\[
x^3 = \frac{10^{21}}{8}
\]
\[
x^3 = 1.25 \times 10^{20}
\]
\[
x = \sqrt[3]{1.25 \times 10^{20}}
\]
\[
x \approx 5 \times 10^6
\]
\[
\boxed{x \approx 5000000}
\]
First, use the properties of logarithms to combine the terms on the left side:
\[
\ln((x+4)x) = \ln(x+40)
\]
Simplify the argument of the logarithm:
\[
\ln(x^2 + 4x) = \ln(x+40)
\]
Since the natural logarithm function is one-to-one, we can equate the arguments:
\[
x^2 + 4x = x + 40
\]
Rearrange the equation to form a quadratic equation:
\[
x^2 + 3x - 40 = 0
\]
Solve the quadratic equation using the quadratic formula \(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\):
\[
x = \frac{-3 \pm \sqrt{3^2 - 4(1)(-40)}}{2(1)}
\]
\[
x = \frac{-3 \pm \sqrt{9 + 160}}{2}
\]
\[
x = \frac{-3 \pm \sqrt{169}}{2}
\]
\[
x = \frac{-3 \pm 13}{2}
\]
This gives us two solutions:
\[
x = \frac{10}{2} = 5 \quad \text{and} \quad x = \frac{-16}{2} = -8
\]
Since \(x\) must be positive (as it is inside a logarithm), we discard \(x = -8\):
\[
\boxed{x = 5}
\]
Given the sales decay function \(S = 80,000 e^{-0.5x}\):
Substitute \(x = 2\) into the function:
\[
S = 80,000 e^{-0.5 \times 2}
\]
\[
S = 80,000 e^{-1}
\]
Using the value of \(e^{-1} \approx 0.3679\):
\[
S \approx 80,000 \times 0.3679
\]
\[
S \approx 29,432
\]
\[
\boxed{S \approx 29,432}
\]
Set \(S = 1,000\) and solve for \(x\):
\[
1,000 = 80,000 e^{-0.5x}
\]
Divide both sides by 80,000:
\[
\frac{1,000}{80,000} = e^{-0.5x}
\]
\[
0.0125 = e^{-0.5x}
\]
Take the natural logarithm of both sides:
\[
\ln(0.0125) = -0.5x
\]
\[
-4.3820 = -0.5x
\]
Solve for \(x\):
\[
x = \frac{4.3820}{0.5}
\]
\[
x \approx 8.764
\]
Rounding up to the nearest whole number:
\[
\boxed{x = 9 \text{ months}}
\]