1. **State the problem:** Solve for $x$ in the equation $$\ln x + \log x = 5$$ where $\ln$ is the natural logarithm (base $e$) and $\log$ is the common logarithm (base 10).
2. **Recall the relationship between logarithms:** We know that $$\log x = \frac{\ln x}{\ln 10}$$ because changing the base of a logarithm uses the formula $$\log_a b = \frac{\log_c b}{\log_c a}$$.
3. **Rewrite the equation using natural logarithms:**
$$\ln x + \frac{\ln x}{\ln 10} = 5$$
4. **Factor out $\ln x$:**
$$\ln x \left(1 + \frac{1}{\ln 10}\right) = 5$$
5. **Simplify the factor:**
$$1 + \frac{1}{\ln 10} = \frac{\ln 10 + 1}{\ln 10}$$
6. **Rewrite the equation:**
$$\ln x \cdot \frac{\ln 10 + 1}{\ln 10} = 5$$
7. **Isolate $\ln x$:**
$$\ln x = 5 \cdot \frac{\ln 10}{\ln 10 + 1}$$
8. **Exponentiate both sides to solve for $x$:**
$$x = e^{5 \cdot \frac{\ln 10}{\ln 10 + 1}}$$
9. **Final answer:**
$$\boxed{x = e^{5 \cdot \frac{\ln 10}{\ln 10 + 1}}}$$
This is the exact solution. You can approximate numerically if needed by substituting $\ln 10 \approx 2.302585$.
Logarithm Equation A8Cb9C
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