Решение:
1) $$(-0,76 - 0,44) : 2\frac{2}{3} = (-1,2) : \frac{8}{3} = -1,2 * \frac{3}{8} = -\frac{1,2 * 3}{8} = -\frac{3,6}{8} = -0,45$$
2) $$(3\frac{5}{14} - 2\frac{3}{4})*(-3\frac{5}{17}) = (3\frac{10}{28} - 2\frac{21}{28})*(-3\frac{5}{17}) = (2\frac{38}{28} - 2\frac{21}{28})*(-3\frac{5}{17}) = \frac{17}{28} * (-\frac{56}{17}) = -\frac{17 * 56}{28 * 17} = -\frac{56}{28} = -2$$
Ответ: 1) -0,45; 2) -2