1. The problem asks to subtract fractions: first $\frac{1}{8} - \frac{3}{9}$, then $\frac{5}{6} - \frac{2}{7}$. 2. To subtract fractions, use the formula: $$\frac{a}{b} - \frac{c}{d} = \frac{ad - bc}{bd}$$ where $a, b, c, d$ are integers and $b, d \neq 0$. 3. For the first problem: $$\frac{1}{8} - \frac{3}{9} = \frac{1 \times 9 - 3 \times 8}{8 \times 9} = \frac{9 - 24}{72} = \frac{-15}{72}$$ 4. Simplify the fraction by dividing numerator and denominator by their greatest common divisor (GCD), which is 3: $$\frac{\cancel{15}}{\cancel{72}} = \frac{-5}{24}$$ 5. For the second problem: $$\frac{5}{6} - \frac{2}{7} = \frac{5 \times 7 - 2 \times 6}{6 \times 7} = \frac{35 - 12}{42} = \frac{23}{42}$$ 6. The fraction $\frac{23}{42}$ cannot be simplified further because 23 is prime and does not divide 42. 7. Final answers: - $\frac{1}{8} - \frac{3}{9} = \frac{-5}{24}$ - $\frac{5}{6} - \frac{2}{7} = \frac{23}{42}$