Question: solve $f(x) + f\left(1 - \frac{1}{x}\right) = 8x$ when $f(2)$
1. **State the problem:** We are given the functional equation $$f(x) + f\left(1 - \frac{1}{x}\right) = 8x$$ and need to find the value of $$f(2)$$.
2. **Use the given equation:** Substitute $$x = 2$$:
$$f(2) + f\left(1 - \frac{1}{2}\right) = 8 \times 2$$
which simplifies to
$$f(2) + f\left(1 - 0.5\right) = 16$$
$$f(2) + f(0.5) = 16$$
3. **Substitute $$x = 0.5$$:**
$$f(0.5) + f\left(1 - \frac{1}{0.5}\right) = 8 \times 0.5$$
Calculate inside the function:
$$1 - \frac{1}{0.5} = 1 - 2 = -1$$
So,
$$f(0.5) + f(-1) = 4$$
4. **Substitute $$x = -1$$:**
$$f(-1) + f\left(1 - \frac{1}{-1}\right) = 8 \times (-1)$$
Calculate inside the function:
$$1 - \frac{1}{-1} = 1 + 1 = 2$$
So,
$$f(-1) + f(2) = -8$$
5. **Now we have a system of three equations:**
$$\begin{cases}
f(2) + f(0.5) = 16 \\
f(0.5) + f(-1) = 4 \\
f(-1) + f(2) = -8
\end{cases}$$
6. **Add all three equations:**
$$[f(2) + f(0.5)] + [f(0.5) + f(-1)] + [f(-1) + f(2)] = 16 + 4 - 8$$
Simplify left side:
$$2f(2) + 2f(0.5) + 2f(-1) = 12$$
Divide both sides by 2:
$$f(2) + f(0.5) + f(-1) = 6$$
7. **Use the first equation to substitute $$f(0.5) = 16 - f(2)$$ and the second to substitute $$f(-1) = 4 - f(0.5)$$:**
Substitute $$f(0.5)$$ in $$f(-1)$$:
$$f(-1) = 4 - (16 - f(2)) = 4 - 16 + f(2) = f(2) - 12$$
8. **Substitute both into the sum:**
$$f(2) + (16 - f(2)) + (f(2) - 12) = 6$$
Simplify:
$$f(2) + 16 - f(2) + f(2) - 12 = 6$$
$$f(2) + 4 = 6$$
9. **Solve for $$f(2)$$:**
$$f(2) = 6 - 4 = 2$$
**Final answer:** $$\boxed{2}$$