Общий знаменатель 72. \(\frac{1 \times 4}{18 \times 4} + \frac{1 \times 3}{24 \times 3} = \frac{4}{72} + \frac{3}{72} = \frac{7}{72}\)
Общий знаменатель 78. \(\frac{9 \times 6}{13 \times 6} + \frac{5 \times 3}{26 \times 3} + \frac{1}{78} = \frac{54}{78} + \frac{15}{78} + \frac{1}{78} = \frac{70}{78} = \frac{35}{39}\)
Приведём к общему знаменателю 98. \(4\frac{15 \times 2}{49 \times 2} - 2\frac{3 \times 7}{14 \times 7} = 4\frac{30}{98} - 2\frac{21}{98} = (4-2) + (\frac{30}{98} - \frac{21}{98}) = 2\frac{9}{98}\)
Приведём к общему знаменателю 20. \(28\frac{3 \times 5}{4 \times 5} - 10\frac{7 \times 2}{10 \times 2} = 28\frac{15}{20} - 10\frac{14}{20} = (28-10) + (\frac{15}{20} - \frac{14}{20}) = 18\frac{1}{20}\)
\(\frac{8}{15} \cdot \frac{28}{25} = \frac{8 \times 28}{15 \times 25} = \frac{224}{375}\)
\(\frac{1}{6} \cdot \frac{8 \times 5 + 2}{5} = \frac{1}{6} \cdot \frac{42}{5} = \frac{1 \times 42}{6 \times 5} = \frac{42}{30} = \frac{7}{5} = 1\frac{2}{5}\)
\(\frac{4 \times 9 + 7}{9} \cdot \frac{4}{8} = \frac{43}{9} \cdot \frac{4}{8} = \frac{43 \times 4}{9 \times 8} = \frac{172}{72} = \frac{43}{18} = 2\frac{7}{18}\)
\(\frac{10 \times 7 + 2}{7} : \frac{1 \times 9 + 2}{9} = \frac{72}{7} : \frac{11}{9} = \frac{72}{7} \cdot \frac{9}{11} = \frac{72 \times 9}{7 \times 11} = \frac{648}{77}\)
\(\frac{5}{9} \cdot \frac{4 \times 8 + 7}{8} = \frac{5}{9} \cdot \frac{39}{8} = \frac{5 \times 39}{9 \times 8} = \frac{195}{72} = \frac{65}{24} = 2\frac{17}{24}\)
\((\frac{1 \times 2 + 1}{2})^3 = (\frac{3}{2})^3 = \frac{3^3}{2^3} = \frac{27}{8} = 3\frac{3}{8}\)
\(\frac{1}{2} \cdot \frac{4}{1} = \frac{4}{2} = 2\)
\(\frac{150}{225} = \frac{150 \div 75}{225 \div 75} = \frac{2}{3}\)
\(3\frac{1}{4} = \frac{3 \times 4 + 1}{4} = \frac{13}{4}\)
\(\frac{5}{7}\)
\(\frac{7}{48} \cdot \frac{7}{6} = \frac{7 \times 7}{48 \times 6} = \frac{49}{288}\)
\(\frac{15 \times 24 + 7}{24} : \frac{3 \times 120 + 7}{120} = \frac{367}{24} : \frac{367}{120} = \frac{367}{24} \cdot \frac{120}{367} = \frac{120}{24} = 5\)
\(\frac{2 \times 23 + 3}{23} : \frac{21}{46} = \frac{49}{23} : \frac{21}{46} = \frac{49}{23} \cdot \frac{46}{21} = \frac{49 \times 46}{23 \times 21} = \frac{49 \times 2}{21} = \frac{7 \times 2}{3} = \frac{14}{3} = 4\frac{2}{3}\)
\(\frac{11 \times 7 \times 21}{12 \times 24 \times 22} = \frac{7 \times 21}{12 \times 24 \times 2} = \frac{7 \times 7}{4 \times 24 \times 2} = \frac{49}{192}\)
\(\frac{5}{7}\)
\(\frac{11}{7}\)
\(\frac{21}{22}\)