Найди значение числового выражения: 1/120 + 4/15

- a) $$\frac{1}{120} + \frac{4}{15} = \frac{1}{120} + \frac{32}{120} = \frac{33}{120} = \frac{11}{40}$$ - б) $$5\frac{3}{8} + 4\frac{5}{6} = 5 + \frac{3}{8} + 4 + \frac{5}{6} = 9 + \frac{9}{24} + \frac{20}{24} = 9 + \frac{29}{24} = 9 + 1\frac{5}{24} = 10\frac{5}{24}$$ - в) $$5\frac{4}{9} - 1\frac{2}{3} = 5\frac{4}{9} - 1\frac{6}{9} = 4\frac{13}{9} - 1\frac{6}{9} = 3\frac{7}{9}$$ - г) $$7\frac{3}{5} - (1\frac{2}{9} + 2\frac{3}{5}) = 7\frac{3}{5} - (1\frac{10}{45} + 2\frac{27}{45}) = 7\frac{3}{5} - 3\frac{37}{45} = 7\frac{27}{45} - 3\frac{37}{45} = 6\frac{72}{45} - 3\frac{37}{45} = 3\frac{35}{45} = 3\frac{7}{9}$$ - д) $$\frac{8}{35} \cdot \frac{49}{64} = \frac{8 \cdot 49}{35 \cdot 64} = \frac{1 \cdot 7}{5 \cdot 8} = \frac{7}{40}$$ - е) $$10\frac{4}{5} \cdot 4\frac{3}{8} = \frac{54}{5} \cdot \frac{35}{8} = \frac{54 \cdot 35}{5 \cdot 8} = \frac{54 \cdot 7}{1 \cdot 8} = \frac{27 \cdot 7}{1 \cdot 4} = \frac{189}{4} = 47\frac{1}{4}$$ - ж) $$\frac{15}{22} : \frac{10}{77} = \frac{15}{22} \cdot \frac{77}{10} = \frac{15 \cdot 77}{22 \cdot 10} = \frac{3 \cdot 7}{2 \cdot 2} = \frac{21}{4} = 5\frac{1}{4}$$ - з) $$4\frac{6}{7} : 3\frac{9}{14} = \frac{34}{7} : \frac{51}{14} = \frac{34}{7} \cdot \frac{14}{51} = \frac{34 \cdot 14}{7 \cdot 51} = \frac{2 \cdot 2}{1 \cdot 3} = \frac{4}{3} = 1\frac{1}{3}$$ - и) $$6\frac{5}{8} \cdot 3\frac{1}{5} : 7\frac{1}{15} = \frac{53}{8} \cdot \frac{16}{5} : \frac{106}{15} = \frac{53 \cdot 16}{8 \cdot 5} \cdot \frac{15}{106} = \frac{53 \cdot 2}{1 \cdot 5} \cdot \frac{3}{106} = \frac{1 \cdot 2}{1 \cdot 1} \cdot \frac{3}{2} = \frac{6}{5} = 1\frac{1}{5}$$ - к) $$-3,6 + 11,5 = 7,9$$ - л) $$-19,1 - 5,7 = -24,8$$ - м) $$-3,1 - (-5,9) = -3,1 + 5,9 = 2,8$$ - н) $$-13,6 + 8,7 = -4,9$$ - о) $$-3\frac{5}{12} + 1\frac{11}{18} = -3\frac{15}{36} + 1\frac{22}{36} = -2\frac{57}{36} + 1\frac{22}{36} = -1\frac{35}{36}$$ - п) $$-8\frac{11}{30} + 6,9 = -8\frac{11}{30} + 6\frac{9}{10} = -8\frac{11}{30} + 6\frac{27}{30} = -2\frac{11}{30} + \frac{27}{30} = -1\frac{41}{30} + \frac{27}{30} = -1\frac{14}{30} = -1\frac{7}{15}$$ - p) $$1,6 \cdot (-4,5) = -7,2$$ - с) $$-135,2 : (-6,5) = 20,8$$ - т) $$(-1\frac{7}{8}) \cdot 1\frac{1}{3} = (-\frac{15}{8}) \cdot \frac{4}{3} = -\frac{15 \cdot 4}{8 \cdot 3} = -\frac{5 \cdot 1}{2 \cdot 1} = -\frac{5}{2} = -2\frac{1}{2}$$ - у) $$1\frac{2}{3} : (-3\frac{1}{3}) = \frac{5}{3} : (-\frac{10}{3}) = \frac{5}{3} \cdot (-\frac{3}{10}) = -\frac{5 \cdot 3}{3 \cdot 10} = -\frac{1 \cdot 1}{1 \cdot 2} = -\frac{1}{2}$$ **Ответы:** - a) $\frac{11}{40}$ - б) $10\frac{5}{24}$ - в) $3\frac{7}{9}$ - г) $3\frac{7}{9}$ - д) $\frac{7}{40}$ - е) $47\frac{1}{4}$ - ж) $5\frac{1}{4}$ - з) $1\frac{1}{3}$ - и) $1\frac{1}{5}$ - к) $7,9$ - л) $-24,8$ - м) $2,8$ - н) $-4,9$ - о) $-1\frac{35}{36}$ - п) $-1\frac{7}{15}$ - p) $-7,2$ - с) $20,8$ - т) $-2\frac{1}{2}$ - у) $-\frac{1}{2}$