Вычислите значения выражений: а) 1 7/15 + 2 3/15 - 1 8/15 - 1 4/15; б) 3 12/13 - 1 5/13 - 1 9/13 + 2 3/13; а) (5 - 3 7/16) + (4 - 2 9/16); в) 3 2/17 + 1 12/17 + 2 3/17 - 3 8/17; г) 5 3/14 - 1 5/14 + 2 9/14 - 4 13/14; в) (2 - 1 5/9) + (4 - 1 4/9)

**Ответ:** а) $1 \frac{7}{15} + 2 \frac{3}{15} - 1 \frac{8}{15} - 1 \frac{4}{15} = \frac{13}{15}$ б) $3 \frac{12}{13} - 1 \frac{5}{13} - 1 \frac{9}{13} + 2 \frac{3}{13} = 3 \frac{1}{13}$ а) $(5 - 3 \frac{7}{16}) + (4 - 2 \frac{9}{16}) = 3$ в) $3 \frac{2}{17} + 1 \frac{12}{17} + 2 \frac{3}{17} - 3 \frac{8}{17} = 3 \frac{9}{17}$ г) $5 \frac{3}{14} - 1 \frac{5}{14} + 2 \frac{9}{14} - 4 \frac{13}{14} = 1 \frac{8}{14} = 1 \frac{4}{7}$ в) $(2 - 1 \frac{5}{9}) + (4 - 1 \frac{4}{9}) = 3$ **Решение:** а) $1 \frac{7}{15} + 2 \frac{3}{15} - 1 \frac{8}{15} - 1 \frac{4}{15} = (1+2-1-1) + \frac{7+3-8-4}{15} = 1 - \frac{2}{15} = \frac{15}{15} - \frac{2}{15} = \frac{13}{15}$ б) $3 \frac{12}{13} - 1 \frac{5}{13} - 1 \frac{9}{13} + 2 \frac{3}{13} = (3-1-1+2) + \frac{12-5-9+3}{13} = 3 + \frac{1}{13} = 3 \frac{1}{13}$ а) $5 - 3 \frac{7}{16} = 4 \frac{16}{16} - 3 \frac{7}{16} = 1 \frac{9}{16}$; $4 - 2 \frac{9}{16} = 3 \frac{16}{16} - 2 \frac{9}{16} = 1 \frac{7}{16}$; $1 \frac{9}{16} + 1 \frac{7}{16} = 2 \frac{16}{16} = 3$ в) $3 \frac{2}{17} + 1 \frac{12}{17} + 2 \frac{3}{17} - 3 \frac{8}{17} = (3+1+2-3) + \frac{2+12+3-8}{17} = 3 + \frac{9}{17} = 3 \frac{9}{17}$ г) $5 \frac{3}{14} - 1 \frac{5}{14} + 2 \frac{9}{14} - 4 \frac{13}{14} = (4 \frac{17}{14} - 1 \frac{5}{14}) + 2 \frac{9}{14} - 4 \frac{13}{14} = 3 \frac{12}{14} + 2 \frac{9}{14} - 4 \frac{13}{14} = 5 \frac{21}{14} - 4 \frac{13}{14} = 1 \frac{8}{14} = 1 \frac{4}{7}$ в) $2 - 1 \frac{5}{9} = 1 \frac{9}{9} - 1 \frac{5}{9} = \frac{4}{9}$; $4 - 1 \frac{4}{9} = 3 \frac{9}{9} - 1 \frac{4}{9} = 2 \frac{5}{9}$; $\frac{4}{9} + 2 \frac{5}{9} = 2 \frac{9}{9} = 3$