Ответ:

а) \(2-\frac{1}{3}=\frac{6}{3}-\frac{1}{3}=\frac{5}{3}=1\frac{2}{3}\).

б) \(4\frac{6}{7}=\frac{34}{7}\), \(2\frac{8}{9}=\frac{26}{9}\).

\(\frac{34}{7}-\frac{26}{9}=\frac{306-182}{63}=\frac{124}{63}=1\frac{61}{63}\).

Ответ: а) \(1\frac{2}{3}\); б) \(1\frac{61}{63}\).