Решение:

1. a) $$\frac{11}{20} - \frac{3}{16} + \frac{3}{40} = \frac{11 \cdot 4}{20 \cdot 4} - \frac{3 \cdot 5}{16 \cdot 5} + \frac{3 \cdot 2}{40 \cdot 2} = \frac{44}{80} - \frac{15}{80} + \frac{6}{80} = \frac{44 - 15 + 6}{80} = \frac{35}{80} = \frac{7}{16}$$
2. б) $$6 - 2\frac{10}{13} = 6 - \frac{2 \cdot 13 + 10}{13} = 6 - \frac{26 + 10}{13} = 6 - \frac{36}{13} = \frac{6 \cdot 13}{13} - \frac{36}{13} = \frac{78}{13} - \frac{36}{13} = \frac{78 - 36}{13} = \frac{42}{13} = 3\frac{3}{13}$$
3. в) $$7\frac{3}{8} + 1\frac{7}{10} = \frac{7 \cdot 8 + 3}{8} + \frac{1 \cdot 10 + 7}{10} = \frac{56 + 3}{8} + \frac{10 + 7}{10} = \frac{59}{8} + \frac{17}{10} = \frac{59 \cdot 5}{8 \cdot 5} + \frac{17 \cdot 4}{10 \cdot 4} = \frac{295}{40} + \frac{68}{40} = \frac{295 + 68}{40} = \frac{363}{40} = 9\frac{3}{40}$$
4. г) $$4\frac{11}{12} + 5\frac{13}{18} = \frac{4 \cdot 12 + 11}{12} + \frac{5 \cdot 18 + 13}{18} = \frac{48 + 11}{12} + \frac{90 + 13}{18} = \frac{59}{12} + \frac{103}{18} = \frac{59 \cdot 3}{12 \cdot 3} + \frac{103 \cdot 2}{18 \cdot 2} = \frac{177}{36} + \frac{206}{36} = \frac{177 + 206}{36} = \frac{383}{36} = 10\frac{23}{36}$$
5. д) $$9\frac{2}{9} - 6\frac{5}{6} = \frac{9 \cdot 9 + 2}{9} - \frac{6 \cdot 6 + 5}{6} = \frac{81 + 2}{9} - \frac{36 + 5}{6} = \frac{83}{9} - \frac{41}{6} = \frac{83 \cdot 2}{9 \cdot 2} - \frac{41 \cdot 3}{6 \cdot 3} = \frac{166}{18} - \frac{123}{18} = \frac{166 - 123}{18} = \frac{43}{18} = 2\frac{7}{18}$$

Ответ:

• a) $$\frac{7}{16}$$
• б) $$3\frac{3}{13}$$
• в) $$9\frac{3}{40}$$
• г) $$10\frac{23}{36}$$
• д) $$2\frac{7}{18}$$