Задание 3. Вычислите: 1) 1 5/36 + 5 1/9; 2) 1 20/32 + 3 1/2; 3) 2 28/35 + 6 1/8; 4) 1 7/16 + 2 5/25; 5) 1 11/20 + 10 5/8; 6) 3 2/15 − 1 21/36; 7) 9 1/4 − 1 8/25; 8) 2 1/4 − 3 2/5; 9) 1 30/32 − 2 3/4; 10) 3 19/24 − 1 3/30; 11) 6 1/4 − 2 9/10; 12) 3 1/6 · 3 9/12; 13) 2 1/20 : 1 12/13; 14) 6 2/7 : 2 12/14; 15) 3 3/5 : 4 5/35.

1. \(1\frac{5}{36}+5\frac{1}{9}=1\frac{5}{36}+5\frac{4}{36}=6\frac{9}{36}=6\frac{1}{4}\).
2. \(1\frac{20}{32}+3\frac{1}{2}=1\frac{5}{8}+3\frac{4}{8}=4\frac{9}{8}=5\frac{1}{8}\).
3. \(2\frac{28}{35}+6\frac{1}{8}=2\frac{4}{5}+6\frac{1}{8}=8+\frac{37}{40}=8\frac{37}{40}\).
4. \(1\frac{7}{16}+2\frac{5}{25}=1\frac{7}{16}+2\frac{1}{5}=3\frac{31}{80}\).
5. \(1\frac{11}{20}+10\frac{5}{8}=11+\frac{22}{40}+\frac{25}{40}=11\frac{47}{40}=12\frac{7}{40}\).
6. \(3\frac{2}{15}-1\frac{21}{36}=3\frac{2}{15}-1\frac{7}{12}=1\frac{8}{60}-\frac{35}{60}=1\frac{33}{60}=1\frac{11}{20}\).
7. \(9\frac{1}{4}-1\frac{8}{25}=8+\frac{25}{100}-\frac{32}{100}=7\frac{93}{100}\).
8. \(2\frac{1}{4}-3\frac{2}{5}=2\frac{5}{20}-3\frac{8}{20}=-1\frac{3}{20}\).
9. \(1\frac{30}{32}-2\frac{3}{4}=1\frac{15}{16}-2\frac{12}{16}=-1\frac{13}{16}\).
10. \(3\frac{19}{24}-1\frac{3}{30}=3\frac{19}{24}-1\frac{1}{10}=2+\frac{95}{120}-\frac{12}{120}=2\frac{83}{120}\).
11. \(6\frac{1}{4}-2\frac{9}{10}=6\frac{5}{20}-2\frac{18}{20}=3\frac{7}{20}\).
12. \(3\frac{1}{6}\cdot3\frac{9}{12}=\frac{19}{6}\cdot\frac{15}{4}=\frac{95}{8}=11\frac{7}{8}\).
13. \(2\frac{1}{20}:1\frac{12}{13}=\frac{41}{20}:\frac{25}{13}=\frac{41}{20}\cdot\frac{13}{25}=\frac{533}{500}=1\frac{33}{500}\).
14. \(6\frac{2}{7}:2\frac{12}{14}=\frac{44}{7}:\frac{24}{7}=\frac{11}{6}=1\frac{5}{6}\).
15. \(3\frac{3}{5}:4\frac{5}{35}=\frac{18}{5}:\frac{29}{7}=\frac{18}{5}\cdot\frac{7}{29}=\frac{126}{145}\).

Ответ: 1) 6 1/4; 2) 5 1/8; 3) 8 37/40; 4) 3 31/80; 5) 12 7/40; 6) 1 11/20; 7) 7 93/100; 8) −1 3/20; 9) −1 13/16; 10) 2 83/120; 11) 3 7/20; 12) 11 7/8; 13) 1 33/500; 14) 1 5/6; 15) 126/145.