Выполните действия с дробями (используйте метод бабочки для нахождения общего знаменателя, не забывайте выделять целую часть в неправильной дроби): А) 8/21 + 3/14, 35/42 + 34/63, 7/24 + 31/40; Б) 7/8 − 5/24, 29/60 − 7/30, 13/15 − 13/20; В) 4 4/5 + 1 1/3, 6 1/6 + 2 5/18, 17 3/7 + 5 13/14; Г) 7 7/24 − 3 7/30, 8 7/16 − 4 5/12, 13 1/15 − 4 7/20, 10 5/28 − 7 37/42; Д) 1 12/13 · 13/15, 4 4/11 · 3 7/16, 2 14/15 · 3 2/11; Е) 2 1/3 : 1 1/4, 11 1/4 : 1 2/7.

А)

\(\frac{8}{21}+\frac{3}{14}=\frac{16}{42}+\frac{9}{42}=\frac{25}{42}\).

\(\frac{35}{42}+\frac{34}{63}=\frac{105}{126}+\frac{68}{126}=\frac{173}{126}=1\frac{47}{126}\).

\(\frac{7}{24}+\frac{31}{40}=\frac{35}{120}+\frac{93}{120}=\frac{128}{120}=1\frac{2}{15}\).

Б)

\(\frac{7}{8}-\frac{5}{24}=\frac{21}{24}-\frac{5}{24}=\frac{16}{24}=\frac{2}{3}\).

\(\frac{29}{60}-\frac{7}{30}=\frac{29}{60}-\frac{14}{60}=\frac{15}{60}=\frac{1}{4}\).

\(\frac{13}{15}-\frac{13}{20}=\frac{52}{60}-\frac{39}{60}=\frac{13}{60}\).

В)

\(4\frac{4}{5}+1\frac{1}{3}=\frac{24}{5}+\frac{4}{3}=\frac{72}{15}+\frac{20}{15}=\frac{92}{15}=6\frac{2}{15}\).

\(6\frac{1}{6}+2\frac{5}{18}=\frac{37}{6}+\frac{41}{18}=\frac{111}{18}+\frac{41}{18}=\frac{152}{18}=8\frac{2}{9}\).

\(17\frac{3}{7}+5\frac{13}{14}=\frac{122}{7}+\frac{83}{14}=\frac{244}{14}+\frac{83}{14}=\frac{327}{14}=23\frac{5}{14}\).

Г)

\(7\frac{7}{24}-3\frac{7}{30}=\frac{175}{24}-\frac{97}{30}=\frac{875}{120}-\frac{388}{120}=\frac{487}{120}=4\frac{7}{120}\).

\(8\frac{7}{16}-4\frac{5}{12}=\frac{135}{16}-\frac{53}{12}=\frac{405}{48}-\frac{212}{48}=\frac{193}{48}=4\frac{1}{48}\).

\(13\frac{1}{15}-4\frac{7}{20}=\frac{196}{15}-\frac{87}{20}=\frac{784}{60}-\frac{261}{60}=\frac{523}{60}=8\frac{43}{60}\).

\(10\frac{5}{28}-7\frac{37}{42}=\frac{285}{28}-\frac{331}{42}=\frac{855}{84}-\frac{662}{84}=\frac{193}{84}=2\frac{25}{84}\).

Д)

\(1\frac{12}{13}\cdot\frac{13}{15}=\frac{25}{13}\cdot\frac{13}{15}=\frac{5}{3}=1\frac{2}{3}\).

\(4\frac{4}{11}\cdot3\frac{7}{16}=\frac{48}{11}\cdot\frac{55}{16}=15\).

\(2\frac{14}{15}\cdot3\frac{2}{11}=\frac{44}{15}\cdot\frac{35}{11}=\frac{28}{3}=9\frac{1}{3}\).

Е)

\(2\frac{1}{3}:1\frac{1}{4}=\frac{7}{3}:\frac{5}{4}=\frac{7}{3}\cdot\frac{4}{5}=\frac{28}{15}=1\frac{13}{15}\).

\(11\frac{1}{4}:1\frac{2}{7}=\frac{45}{4}:\frac{9}{7}=\frac{45}{4}\cdot\frac{7}{9}=\frac{35}{4}=8\frac{3}{4}\).

Ответ: А) \(\frac{25}{42}; 1\frac{47}{126}; 1\frac{2}{15}\). Б) \(\frac{2}{3}; \frac{1}{4}; \frac{13}{60}\). В) \(6\frac{2}{15}; 8\frac{2}{9}; 23\frac{5}{14}\). Г) \(4\frac{7}{120}; 4\frac{1}{48}; 8\frac{43}{60}; 2\frac{25}{84}\). Д) \(1\frac{2}{3}; 15; 9\frac{1}{3}\). Е) \(1\frac{13}{15}; 8\frac{3}{4}\).