з) -3\frac{7}{12} - 2\frac{5}{8}.

з) -3\frac{7}{12} - 2\frac{5}{8} = -\frac{3 * 12 + 7}{12} - \frac{2 * 8 + 5}{8} = -\frac{43}{12} - \frac{21}{8} = -\frac{43 * 2}{12 * 2} - \frac{21 * 3}{8 * 3} = -\frac{86}{24} - \frac{63}{24} = \frac{-86 - 63}{24} = \frac{-149}{24} = -6\frac{5}{24}