2.Выполнить действия с обыкновенными дробями:

Решение примеров на действия с обыкновенными дробями: а) $\frac{1}{5} + \frac{1}{3} = \frac{3}{15} + \frac{5}{15} = \frac{8}{15}$ б) $\frac{1}{2} + \frac{3}{8} = \frac{4}{8} + \frac{3}{8} = \frac{7}{8}$ в) $\frac{3}{4} + 2 = 2\frac{3}{4}$ г) $\frac{2}{3} - \frac{1}{6} = \frac{4}{6} - \frac{1}{6} = \frac{3}{6} = \frac{1}{2}$ д) $\frac{7}{12} - 1 = \frac{7}{12} - \frac{12}{12} = -\frac{5}{12}$ е) $\frac{4}{5} - \frac{9}{10} = \frac{8}{10} - \frac{9}{10} = -\frac{1}{10}$ ё) $\frac{1}{3} - \frac{1}{2} = \frac{2}{6} - \frac{3}{6} = -\frac{1}{6}$ ж) $1 + \frac{7}{3} = 1 + 2\frac{1}{3} = 3\frac{1}{3}$ з) $\frac{8}{15} : 4 = \frac{8}{15} \cdot \frac{1}{4} = \frac{2}{15}$ и) $3 : \frac{3}{2} = 3 \cdot \frac{2}{3} = 2$ й) $1 : \frac{3}{4} = 1 \cdot \frac{4}{3} = \frac{4}{3} = 1\frac{1}{3}$ к) $-\frac{7}{12} : (-\frac{1}{4}) = \frac{7}{12} \cdot 4 = \frac{7}{3} = 2\frac{1}{3}$ л) $\frac{1}{4} \cdot 2 = \frac{2}{4} = \frac{1}{2}$ м) $\frac{3}{4} \cdot \frac{4}{9} = \frac{1}{3}$ н) $\frac{7}{9} \cdot \frac{18}{35} = \frac{1}{1} \cdot \frac{2}{5} = \frac{2}{5}$ о) $-\frac{4}{19} \cdot (-\frac{57}{64}) = \frac{1}{1} \cdot \frac{3}{16} = \frac{3}{16}$ п) $2\frac{3}{4} + 3\frac{5}{7} = 2\frac{21}{28} + 3\frac{20}{28} = 5\frac{41}{28} = 6\frac{13}{28}$ р) $-4\frac{2}{3} + 7\frac{1}{2} = -4\frac{4}{6} + 7\frac{3}{6} = 2\frac{5}{6}$ с) $4\frac{1}{3} + \frac{3}{17} = 4\frac{17}{51} + \frac{9}{51} = 4\frac{26}{51}$ т) $-5\frac{2}{5} + 4\frac{1}{3} = -5\frac{6}{15} + 4\frac{5}{15} = -1\frac{1}{15}$ у) $6\frac{1}{2} - 3\frac{3}{4} = 6\frac{2}{4} - 3\frac{3}{4} = 5\frac{6}{4} - 3\frac{3}{4} = 2\frac{3}{4}$ ф) $2\frac{1}{2} - 7\frac{5}{6} = 2\frac{3}{6} - 7\frac{5}{6} = -5\frac{2}{6} = -5\frac{1}{3}$ х) $-4\frac{2}{3} - 7\frac{7}{9} = -4\frac{6}{9} - 7\frac{7}{9} = -11\frac{13}{9} = -12\frac{4}{9}$ ц) $-2\frac{2}{3} - 3\frac{5}{9} = -2\frac{6}{9} - 3\frac{5}{9} = -5\frac{11}{9} = -6\frac{2}{9}$ ч) $2\frac{3}{4} \cdot 5\frac{7}{33} = \frac{11}{4} \cdot \frac{172}{33} = \frac{1}{1} \cdot \frac{43}{3} = \frac{43}{3} = 14\frac{1}{3}$ ш) $-3\frac{1}{2} \cdot 2\frac{2}{5} = -\frac{7}{2} \cdot \frac{12}{5} = -\frac{7}{1} \cdot \frac{6}{5} = -\frac{42}{5} = -8\frac{2}{5}$ щ) $-4\frac{5}{7} \cdot (-2\frac{6}{11}) = \frac{33}{7} \cdot \frac{28}{11} = 3 \cdot 4 = 12$ ъ) $-3\frac{1}{2} \cdot 2\frac{2}{7} = -\frac{7}{2} \cdot \frac{16}{7} = -8$ ы) $4\frac{1}{3} : 2\frac{5}{6} = \frac{13}{3} : \frac{17}{6} = \frac{13}{3} \cdot \frac{6}{17} = \frac{13}{1} \cdot \frac{2}{17} = \frac{26}{17} = 1\frac{9}{17}$ ь) $-7\frac{3}{8} : (-2\frac{1}{16}) = \frac{59}{8} : \frac{33}{16} = \frac{59}{8} \cdot \frac{16}{33} = \frac{59}{1} \cdot \frac{2}{33} = \frac{118}{33} = 3\frac{19}{33}$ э) $-1\frac{1}{3} : 3\frac{1}{6} = -\frac{4}{3} : \frac{19}{6} = -\frac{4}{3} \cdot \frac{6}{19} = -\frac{4}{1} \cdot \frac{2}{19} = -\frac{8}{19}$