6. Вычислите. a) $$8 \frac{2}{3} - (-1 \frac{1}{3}) = $$ $$-9 \frac{3}{5} + 1 \frac{2}{5} = $$ $$10 \frac{2}{11} - 12 \frac{8}{11} = $$ $$6 \frac{1}{2} - 8 \frac{1}{3} = $$

Решение:

1. \( 8 \frac{2}{3} - (-1 \frac{1}{3}) = 8 \frac{2}{3} + 1 \frac{1}{3} = 9 \frac{3}{3} = 10 \)
2. \( -9 \frac{3}{5} + 1 \frac{2}{5} = -9 \frac{3}{5} + \frac{7}{5} = - \frac{45+3}{5} + \frac{7}{5} = - \frac{48}{5} + \frac{7}{5} = - \frac{41}{5} = -8 \frac{1}{5} \)
3. \( 10 \frac{2}{11} - 12 \frac{8}{11} = \frac{112}{11} - \frac{140}{11} = \frac{112 - 140}{11} = - \frac{28}{11} = -2 \frac{6}{11} \)
4. \( 6 \frac{1}{2} - 8 \frac{1}{3} = \frac{13}{2} - \frac{25}{3} = \frac{39}{6} - \frac{50}{6} = \frac{39 - 50}{6} = - \frac{11}{6} = -1 \frac{5}{6} \)

Ответ: 10; $$-8 \frac{1}{5}$$; $$-2 \frac{6}{11}$$; $$-1 \frac{5}{6}$$.