1. **State the problem:** We need to evaluate the expression $$r = \frac{8 - 10}{8 - 10 + 1}$$. 2. **Calculate the numerator:** $$8 - 10 = -2$$. 3. **Calculate the denominator:** $$8 - 10 + 1 = -2 + 1 = -1$$. 4. **Divide numerator by denominator:** $$r = \frac{-2}{-1} = 2$$. 5. **Interpretation:** The value of $$r$$ is 2. **Final answer:** $$r = 2$$.