Решение:
а) $1\frac{1}{3} - 3\frac{2}{3} = (1 - 3) + (\frac{1}{3} - \frac{2}{3}) = -2 - \frac{1}{3} = -2\frac{1}{3}$;
б) $7\frac{2}{5} - (-1\frac{1}{5}) = (7 + 1) + (\frac{2}{5} + \frac{1}{5}) = 8\frac{3}{5}$;
в) $-6\frac{3}{7} + 1\frac{2}{7} = (-6 + 1) + (-\frac{3}{7} + \frac{2}{7}) = -5 -\frac{1}{7} = -5\frac{1}{7}$;
г) $7\frac{2}{9} - 9\frac{8}{9} = (7 - 9) + (\frac{2}{9} - \frac{8}{9}) = -2 - \frac{6}{9} = -2\frac{2}{3}$;
д) $4\frac{1}{2} - 8\frac{1}{3} = (4 - 8) + (\frac{1}{2} - \frac{1}{3}) = -4 + (\frac{3}{6} - \frac{2}{6}) = -4 + \frac{1}{6} = -3\frac{5}{6}$;
е) $6\frac{9}{10} - 12\frac{1}{100} = (6 - 12) + (\frac{9}{10} - \frac{1}{100}) = -6 + (\frac{90}{100} - \frac{1}{100}) = -6 + \frac{89}{100} = -5\frac{11}{100}$;
ж) $-4\frac{2}{5} - 1\frac{1}{2} = (-4 - 1) + (-\frac{2}{5} - \frac{1}{2}) = -5 + (-\frac{4}{10} - \frac{5}{10}) = -5 - \frac{9}{10} = -5\frac{9}{10}$;
з) $-5\frac{1}{3} - 8\frac{2}{9} = (-5 - 8) + (-\frac{1}{3} - \frac{2}{9}) = -13 + (-\frac{3}{9} - \frac{2}{9}) = -13 - \frac{5}{9} = -13\frac{5}{9}$;
и) $-2\frac{1}{5} - 14\frac{1}{10} = (-2 - 14) + (-\frac{1}{5} - \frac{1}{10}) = -16 + (-\frac{2}{10} - \frac{1}{10}) = -16\frac{3}{10}$.
Ответ:
а) $-2\frac{1}{3}$;
б) $8\frac{3}{5}$
в) $-5\frac{1}{7}$;
г) $-2\frac{2}{3}$;
д) $-3\frac{5}{6}$;
е) $-5\frac{11}{100}$;
ж) $-5\frac{9}{10}$;
з) $-13\frac{5}{9}$;
и) $-16\frac{3}{10}$.