(-2+17\12):(3\8-1\6)-3ц1\4=

$( - 2 + \frac{17}{12} ) \div ( \frac{3}{8} - \frac{1}{6} ) - 3 \frac{1}{4} = - 6.05\\ \\ 1) \: - 2 + 1 \frac{5}{12} = - \frac{7}{12} \\ \\ 2) \: \frac{3}{8} - \frac{1}{6} = \frac{9}{24} - \frac{4}{24} = \frac{5}{24} \\ \\ 3) \: - \frac{7}{12} \div \frac{5}{24} = - \frac{7}{12} \times \frac{24}{5} = - \frac{14}{5} = - 2 \frac{4}{5} = - 2.8 \\ \\ 4) \: - 2.8 - 3.25 = - 6.05$

Ответ: -6.05