1. **State the problem:** Solve the equation $$19^{4 - 2x} - 8 = 38$$ and round the solution to the nearest ten-thousand.
2. **Isolate the exponential term:** Add 8 to both sides to get
$$19^{4 - 2x} = 38 + 8$$
$$19^{4 - 2x} = 46$$
3. **Take the logarithm of both sides:** Use the natural logarithm (ln) for convenience:
$$\ln\left(19^{4 - 2x}\right) = \ln(46)$$
4. **Apply the logarithm power rule:**
$$ (4 - 2x) \ln(19) = \ln(46) $$
5. **Solve for $x$:**
$$ 4 - 2x = \frac{\ln(46)}{\ln(19)} $$
$$ -2x = \frac{\ln(46)}{\ln(19)} - 4 $$
$$ x = \frac{4 - \frac{\ln(46)}{\ln(19)}}{2} $$
6. **Calculate the numerical value:**
Calculate the logarithms:
$$ \ln(46) \approx 3.8286 $$
$$ \ln(19) \approx 2.9444 $$
Then,
$$ \frac{\ln(46)}{\ln(19)} \approx \frac{3.8286}{2.9444} \approx 1.3001 $$
Substitute back:
$$ x = \frac{4 - 1.3001}{2} = \frac{2.6999}{2} = 1.34995 $$
7. **Round to the nearest ten-thousand:**
$$ x \approx 1.3500 $$
**Final answer:**
$$ \boxed{1.3500} $$
Exponential Equation Ebd3F9
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