Question: Write the following as a single rational expression.
$\frac{1}{x} - \frac{1}{x - 2}$
1. **State the problem:** We need to write $\frac{1}{x} - \frac{1}{x - 2}$ as a single rational expression.
2. **Formula and rules:** To subtract fractions, find a common denominator and combine the numerators.
3. **Find the common denominator:** The denominators are $x$ and $x - 2$, so the common denominator is $$x(x - 2)$$.
4. **Rewrite each fraction with the common denominator:**
$$\frac{1}{x} = \frac{x - 2}{x(x - 2)}$$
$$\frac{1}{x - 2} = \frac{x}{x(x - 2)}$$
5. **Subtract the numerators:**
$$\frac{x - 2}{x(x - 2)} - \frac{x}{x(x - 2)} = \frac{(x - 2) - x}{x(x - 2)}$$
6. **Simplify the numerator:**
$$ (x - 2) - x = x - 2 - x = -2 $$
7. **Final expression:**
$$\frac{-2}{x(x - 2)}$$
8. **Answer:** The single rational expression is $$\frac{-2}{x(x - 2)}$$.
This matches the option "-2/[x(x−2)] top-left".