Найдите значение выражения: 61 7 5 13 1 a) - (- ) (+ ); 64 12 14 16 2 6)(1-(+)); 11 3 5 11 17 4 12 18

а) $$\frac{61}{64} - (\frac{7}{12} - \frac{5}{14}) \cdot (\frac{13}{16} + \frac{1}{2}) = \frac{61}{64} - (\frac{7 \cdot 7 - 5 \cdot 6}{84}) \cdot (\frac{13 + 8}{16}) = \frac{61}{64} - (\frac{49 - 30}{84}) \cdot (\frac{21}{16}) = \frac{61}{64} - \frac{19}{84} \cdot \frac{21}{16} = \frac{61}{64} - \frac{19}{4 \cdot 21} \cdot \frac{21}{16} = \frac{61}{64} - \frac{19}{64} = \frac{61 - 19}{64} = \frac{42}{64} = \frac{21}{32}$$

б) $$(1 - \frac{11}{17}) \cdot (\frac{3}{4} - \frac{5}{12} + \frac{11}{18}) = (\frac{17 - 11}{17}) \cdot (\frac{3 \cdot 9 - 5 \cdot 3 + 11 \cdot 2}{36}) = \frac{6}{17} \cdot (\frac{27 - 15 + 22}{36}) = \frac{6}{17} \cdot \frac{34}{36} = \frac{6 \cdot 34}{17 \cdot 36} = \frac{6 \cdot 2 \cdot 17}{17 \cdot 6 \cdot 6} = \frac{2}{6} = \frac{1}{3}$$

Ответ: а) $$\frac{21}{32}$$; б) $$\frac{1}{3}$$