1. **State the problem:** Solve the equation $$6^{x-1} = 2^{3x+1}$$ and express the solution in the form $$\frac{\ln a}{\ln b}$$.
2. **Recall the formula and rules:** To solve equations with exponents, take the natural logarithm (ln) of both sides to bring down the exponents.
3. **Apply ln to both sides:**
$$\ln\left(6^{x-1}\right) = \ln\left(2^{3x+1}\right)$$
4. **Use the power rule of logarithms:**
$$ (x-1)\ln 6 = (3x+1)\ln 2 $$
5. **Expand both sides:**
$$ x\ln 6 - \ln 6 = 3x\ln 2 + \ln 2 $$
6. **Group terms with x on one side and constants on the other:**
$$ x\ln 6 - 3x\ln 2 = \ln 6 + \ln 2 $$
7. **Factor out x:**
$$ x(\ln 6 - 3\ln 2) = \ln 6 + \ln 2 $$
8. **Simplify the logarithmic expressions:**
Recall that $$3\ln 2 = \ln 2^3 = \ln 8$$, so
$$ \ln 6 - 3\ln 2 = \ln 6 - \ln 8 = \ln \frac{6}{8} = \ln \frac{3}{4} $$
Also,
$$ \ln 6 + \ln 2 = \ln (6 \times 2) = \ln 12 $$
So the equation becomes:
$$ x \ln \frac{3}{4} = \ln 12 $$
9. **Solve for x:**
$$ x = \frac{\ln 12}{\ln \frac{3}{4}} $$
10. **Final answer:**
$$ x = \frac{\ln 12}{\ln \frac{3}{4}} $$
This is the solution expressed in the form $$\frac{\ln a}{\ln b}$$ with $$a=12$$ and $$b=\frac{3}{4}$$.
Exponential Equation A028Ed
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