Выполним вычисления по действиям и сократим результаты, если это возможно:
1) $$rac{10}{8} + \frac{3}{7} = \frac{10 \cdot 7 + 3 \cdot 8}{8 \cdot 7} = \frac{70 + 24}{56} = \frac{94}{56} = \frac{47}{28} = 1\frac{19}{28}$$
2) $$\frac{12}{4} - \frac{13}{6} = \frac{12 \cdot 6 - 13 \cdot 4}{4 \cdot 6} = \frac{72 - 52}{24} = \frac{20}{24} = \frac{5}{6}$$
3) $$\frac{11}{16} - \frac{5}{8} = \frac{11 - 5 \cdot 2}{16} = \frac{11 - 10}{16} = \frac{1}{16}$$
4) $$\frac{6}{35} + \frac{3}{10} = \frac{6 \cdot 10 + 3 \cdot 35}{35 \cdot 10} = \frac{60 + 105}{350} = \frac{165}{350} = \frac{33}{70}$$
5) $$\frac{8}{15} + \frac{4}{9} = \frac{8 \cdot 9 + 4 \cdot 15}{15 \cdot 9} = \frac{72 + 60}{135} = \frac{132}{135} = \frac{44}{45}$$
6) $$\frac{4}{15} + \frac{7}{12} = \frac{4 \cdot 12 + 7 \cdot 15}{15 \cdot 12} = \frac{48 + 105}{180} = \frac{153}{180} = \frac{17}{20}$$
7) $$\frac{11}{15} - \frac{3}{5} = \frac{11 - 3 \cdot 3}{15} = \frac{11 - 9}{15} = \frac{2}{15}$$
8) $$\frac{5}{6} - \frac{9}{14} = \frac{5 \cdot 14 - 9 \cdot 6}{6 \cdot 14} = \frac{70 - 54}{84} = \frac{16}{84} = \frac{4}{21}$$
9) $$4\frac{2}{5} + \frac{4}{15} = \frac{4 \cdot 5 + 2}{5} + \frac{4}{15} = \frac{22}{5} + \frac{4}{15} = \frac{22 \cdot 3 + 4}{15} = \frac{66 + 4}{15} = \frac{70}{15} = \frac{14}{3} = 4\frac{2}{3}$$
10) $$\frac{7}{8} + \frac{11}{12} - \frac{5}{6} = \frac{7 \cdot 3 + 11 \cdot 2 - 5 \cdot 4}{24} = \frac{21 + 22 - 20}{24} = \frac{23}{24}$$
11) $$2\frac{2}{5} + 1\frac{1}{3} - \frac{7}{30} = \frac{12}{5} + \frac{4}{3} - \frac{7}{30} = \frac{12 \cdot 6 + 4 \cdot 10 - 7}{30} = \frac{72 + 40 - 7}{30} = \frac{105}{30} = \frac{7}{2} = 3\frac{1}{2}$$
12) $$3\frac{3}{4} + \frac{2}{9} - \frac{5}{36} = \frac{15}{4} + \frac{2}{9} - \frac{5}{36} = \frac{15 \cdot 9 + 2 \cdot 4 - 5}{36} = \frac{135 + 8 - 5}{36} = \frac{138}{36} = \frac{23}{6} = 3\frac{5}{6}$$
13) $$\frac{8}{9} + \frac{5}{6} + \frac{1}{3} = \frac{8 \cdot 2 + 5 \cdot 3 + 1 \cdot 6}{18} = \frac{16 + 15 + 6}{18} = \frac{37}{18} = 2\frac{1}{18}$$
14) $$\frac{9}{16} + \frac{5}{6} + \frac{7}{12} = \frac{9 \cdot 3 + 5 \cdot 8 + 7 \cdot 4}{48} = \frac{27 + 40 + 28}{48} = \frac{95}{48} = 1\frac{47}{48}$$
15) $$5\frac{3}{6} + \frac{5}{4} - \frac{5}{24} = \frac{33}{6} + \frac{5}{4} - \frac{5}{24} = \frac{33 \cdot 4 + 5 \cdot 6 - 5}{24} = \frac{132 + 30 - 5}{24} = \frac{157}{24} = 6\frac{13}{24}$$