Answer: Solve. a. \( 3 \frac{1}{4}-1 \frac{5}{6}= \) b. \( \frac{6}{7}-\frac{5}{9}= \)

To solve \( 3 \frac{1}{4}-1 \frac{5}{6} \), first convert the mixed numbers into improper fractions: \( 3 \frac{1}{4} = \frac{13}{4} \) and \( 1 \frac{5}{6} = \frac{11}{6} \). Next, find a common denominator, which is 12: \( \frac{13}{4} = \frac{39}{12} \) and \( \frac{11}{6} = \frac{22}{12} \). Now, subtract: \( \frac{39}{12} - \frac{22}{12} = \frac{17}{12} \) or \( 1 \frac{5}{12} \). For \( \frac{6}{7}-\frac{5}{9} \), find a common denominator, which is 63: \( \frac{6}{7} = \frac{54}{63} \) and \( \frac{5}{9} = \frac{35}{63} \). Now, subtract: \( \frac{54}{63} - \frac{35}{63} = \frac{19}{63} \). So, the final answers are \( 1 \frac{5}{12} \) for part (a) and \( \frac{19}{63} \) for part (b).