Краткий ответ:
- \(1\dfrac{5}{36}\)
- \(1\dfrac{5}{18}\)
- \(1\dfrac{1}{18}\)
- \(1\dfrac{21}{40}\)
- \(1\dfrac{1}{20}\)
- \(1\dfrac{1}{15}\)
- \(1\dfrac{4}{45}\)
- \(1\dfrac{3}{44}\)
- \(1\dfrac{23}{30}\)
- \(1\dfrac{3}{40}\)
- \(1\dfrac{1}{12}\)
- \(1\dfrac{35}{72}\)
- \(1\dfrac{17}{36}\)
- \(1\dfrac{13}{21}\)
- \(1\dfrac{1}{24}\)
- \(1\dfrac{1}{48}\)
- \(1\dfrac{5}{24}\)
- \(1\dfrac{23}{33}\)
- \(1\dfrac{7}{12}\)
- \(1\dfrac{31}{56}\)
Полное решение:
\[ \begin{aligned} (1)\quad &\frac{11}{12}+\frac{2}{9} =\frac{33}{36}+\frac{8}{36} =\frac{41}{36} =1\frac{5}{36};\\[4pt] (2)\quad &\frac{5}{6}+\frac{4}{9} =\frac{15}{18}+\frac{8}{18} =\frac{23}{18} =1\frac{5}{18};\\[4pt] (3)\quad &\frac{5}{6}+\frac{2}{9} =\frac{15}{18}+\frac{4}{18} =\frac{19}{18} =1\frac{1}{18};\\[4pt] (4)\quad &\frac{9}{10}+\frac{5}{8} =\frac{36}{40}+\frac{25}{40} =\frac{61}{40} =1\frac{21}{40};\\[4pt] (5)\quad &\frac{3}{10}+\frac{3}{4} =\frac{6}{20}+\frac{15}{20} =\frac{21}{20} =1\frac{1}{20};\\[4pt] (6)\quad &\frac{1}{6}+\frac{9}{10} =\frac{5}{30}+\frac{27}{30} =\frac{32}{30} =\frac{16}{15} =1\frac{1}{15};\\[4pt] (7)\quad &\frac{2}{9}+\frac{13}{15} =\frac{10}{45}+\frac{39}{45} =\frac{49}{45} =1\frac{4}{45};\\[4pt] (8)\quad &\frac{3}{4}+\frac{7}{22} =\frac{33}{44}+\frac{14}{44} =\frac{47}{44} =1\frac{3}{44};\\[4pt] (9)\quad &\frac{14}{15}+\frac{5}{6} =\frac{28}{30}+\frac{25}{30} =\frac{53}{30} =1\frac{23}{30};\\[4pt] (10)\quad &\frac{3}{8}+\frac{7}{10} =\frac{15}{40}+\frac{28}{40} =\frac{43}{40} =1\frac{3}{40};\\[4pt] (11)\quad &\frac{5}{6}+\frac{1}{4} =\frac{10}{12}+\frac{3}{12} =\frac{13}{12} =1\frac{1}{12};\\[4pt] (12)\quad &\frac{7}{8}+\frac{11}{18} =\frac{63}{72}+\frac{44}{72} =\frac{107}{72} =1\frac{35}{72};\\[4pt] (13)\quad &\frac{3}{4}+\frac{13}{18} =\frac{27}{36}+\frac{26}{36} =\frac{53}{36} =1\frac{17}{36};\\[4pt] (14)\quad &\frac{5}{6}+\frac{11}{14} =\frac{35}{42}+\frac{33}{42} =\frac{68}{42} =\frac{34}{21} =1\frac{13}{21};\\[4pt] (15)\quad &\frac{5}{12}+\frac{5}{8} =\frac{10}{24}+\frac{15}{24} =\frac{25}{24} =1\frac{1}{24};\\[4pt] (16)\quad &\frac{3}{16}+\frac{5}{6} =\frac{9}{48}+\frac{40}{48} =\frac{49}{48} =1\frac{1}{48};\\[4pt] (17)\quad &\frac{3}{8}+\frac{5}{6} =\frac{9}{24}+\frac{20}{24} =\frac{29}{24} =1\frac{5}{24};\\[4pt] (18)\quad &\frac{19}{22}+\frac{5}{6} =\frac{57}{66}+\frac{55}{66} =\frac{112}{66} =\frac{56}{33} =1\frac{23}{33};\\[4pt] (19)\quad &\frac{3}{4}+\frac{5}{6} =\frac{9}{12}+\frac{10}{12} =\frac{19}{12} =1\frac{7}{12};\\[4pt] (20)\quad &\frac{13}{14}+\frac{5}{8} =\frac{52}{56}+\frac{35}{56} =\frac{87}{56} =1\frac{31}{56}. \end{aligned} \]
Правило: сначала приводим дроби к общему знаменателю, затем складываем числители. Если дробь неправильная, выделяем целую часть и сокращаем дробную часть.
В №7 нужно было взять \(39\), а не \(26\); в №17 общий знаменатель равен \(24\), а не \(16\). В №14 результат \(\frac{68}{42}\) нужно сократить.
Проверка, например:
\[ 1\frac{5}{24}=\frac{29}{24} =\frac{9}{24}+\frac{20}{24} =\frac{3}{8}+\frac{5}{6}. \]
