Найдите сумму: 1) 4 5/9 + 7 1/6; Вычислите значение выражения: 1) 8 9/14 - 3 3/7; Решите уравнение: 1) x + 7 5/15 = 9 7/10

276. Найдите сумму: 1) $4 \frac{5}{9} + 7 \frac{1}{6} = 4 \frac{10}{18} + 7 \frac{3}{18} = 11 \frac{13}{18}$ 2) $6 \frac{11}{12} + 8 \frac{13}{18} = 6 \frac{33}{36} + 8 \frac{26}{36} = 14 \frac{59}{36} = 15 \frac{23}{36}$ 3) $2 \frac{3}{16} + 1 \frac{7}{24} + 3 \frac{1}{12} = 2 \frac{9}{48} + 1 \frac{14}{48} + 3 \frac{4}{48} = 6 \frac{27}{48} = 6 \frac{9}{16}$ 277. Найдите сумму: 1) $5 \frac{7}{8} + 6 \frac{3}{10} = 5 \frac{35}{40} + 6 \frac{12}{40} = 11 \frac{47}{40} = 12 \frac{7}{40}$ 2) $6 \frac{3}{8} + 2 \frac{5}{9} = 6 \frac{27}{72} + 2 \frac{40}{72} = 8 \frac{67}{72}$ 3) $1 \frac{8}{21} + 4 \frac{3}{14} + 2 \frac{2}{7} = 1 \frac{16}{42} + 4 \frac{9}{42} + 2 \frac{12}{42} = 7 \frac{37}{42}$ 278. Вычислите значение выражения: 1) $8 \frac{9}{14} - 3 \frac{3}{7} = 8 \frac{9}{14} - 3 \frac{6}{14} = 5 \frac{3}{14}$ 2) $7 \frac{5}{12} - 3 \frac{7}{24} = 7 \frac{10}{24} - 3 \frac{7}{24} = 4 \frac{3}{24} = 4 \frac{1}{8}$ 3) $12 \frac{11}{12} - 5 \frac{13}{18} = 12 \frac{33}{36} - 5 \frac{26}{36} = 7 \frac{7}{36}$ 279. Выполните вычитание: 1) $3 \frac{1}{12} - ?rac{1}{6} = 3 \frac{1}{12} - ?rac{2}{12} = 2 \frac{13}{12} - ?rac{2}{12} = 2 \frac{11}{12}$ 2) $8 \frac{7}{30} - 2 \frac{9}{20} = 8 \frac{14}{60} - 2 \frac{27}{60} = 7 \frac{74}{60} - 2 \frac{27}{60} = 5 \frac{47}{60}$ 3) $7 \frac{10}{51} - 4 \frac{21}{34} = 7 \frac{20}{102} - 4 \frac{63}{102} = 6 \frac{122}{102} - 4 \frac{63}{102} = 2 \frac{59}{102}$ 4) $5 \frac{1}{4} - 1 \frac{3}{8} = 5 \frac{2}{8} - 1 \frac{3}{8} = 4 \frac{10}{8} - 1 \frac{3}{8} = 3 \frac{7}{8}$ 280. Выполните вычитание: 1) $4 \frac{3}{16} - ?rac{5}{8} = 4 \frac{3}{16} - ?rac{10}{16} = 3 \frac{19}{16} - ?rac{10}{16} = 3 \frac{9}{16}$ 2) $6 \frac{4}{9} - 3 \frac{6}{7} = 6 \frac{28}{63} - 3 \frac{54}{63} = 5 \frac{91}{63} - 3 \frac{54}{63} = 2 \frac{37}{63}$ 3) $10 \frac{11}{24} - 8 \frac{19}{36} = 10 \frac{33}{72} - 8 \frac{38}{72} = 9 \frac{105}{72} - 8 \frac{38}{72} = 1 \frac{67}{72}$ 4) $9 \frac{1}{6} - 5 \frac{3}{4} = 9 \frac{2}{12} - 5 \frac{9}{12} = 8 \frac{14}{12} - 5 \frac{9}{12} = 3 \frac{5}{12}$ 281. Решите уравнение: 1) $x + 7 \frac{5}{15} = 9 \frac{7}{10} \Rightarrow x = 9 \frac{7}{10} - 7 \frac{5}{15} = 9 \frac{21}{30} - 7 \frac{10}{30} = 2 \frac{11}{30}$ 2) $8 \frac{9}{14} - x = 4 \frac{3}{7} \Rightarrow x = 8 \frac{9}{14} - 4 \frac{6}{14} = 4 \frac{3}{14}$ 3) $x - 3 \frac{5}{9} = 5 \frac{1}{12} \Rightarrow x = 5 \frac{1}{12} + 3 \frac{5}{9} = 5 \frac{3}{36} + 3 \frac{20}{36} = 8 \frac{23}{36}$ 282. Решите уравнение: 1) $6 \frac{3}{11} + x = 10 \frac{6}{7} \Rightarrow x = 10 \frac{6}{7} - 6 \frac{3}{11} = 10 \frac{66}{77} - 6 \frac{21}{77} = 4 \frac{45}{77}$ 2) $9 \frac{5}{36} - x = 2 \frac{4}{9} \Rightarrow x = 9 \frac{5}{36} - 2 \frac{16}{36} = 8 \frac{41}{36} - 2 \frac{16}{36} = 6 \frac{25}{36}$ 3) $x - 5 \frac{17}{60} = 7 \frac{9}{20} \Rightarrow x = 7 \frac{9}{20} + 5 \frac{17}{60} = 7 \frac{27}{60} + 5 \frac{17}{60} = 12 \frac{44}{60} = 12 \frac{11}{15}$ 283. Преобразуйте десятичные дроби в обыкновенные и вычислите: 1) $0,8 - \frac{5}{7} = \frac{4}{5} - \frac{5}{7} = \frac{28}{35} - \frac{25}{35} = \frac{3}{35}$ 2) $0,36 + \frac{8}{15} = \frac{36}{100} + \frac{8}{15} = \frac{9}{25} + \frac{8}{15} = \frac{27}{75} + \frac{40}{75} = \frac{67}{75}$ 3) $7 \frac{7}{8} - 3,18 = 7,875 - 3,18 = 4,695 = 4 \frac{139}{200}$ 4) $4,75 - 2 \frac{3}{16} = 4 \frac{3}{4} - 2 \frac{3}{16} = 4 \frac{12}{16} - 2 \frac{3}{16} = 2 \frac{9}{16}$ 284. Преобразуйте десятичные дроби в обыкновенные и вычислите: 1) $0,5 + \frac{1}{3} = \frac{1}{2} + \frac{1}{3} = \frac{3}{6} + \frac{2}{6} = \frac{5}{6}$ 2) $\frac{2}{3} - 0,25 = \frac{2}{3} - \frac{1}{4} = \frac{8}{12} - \frac{3}{12} = \frac{5}{12}$ 3) $0,125 + \frac{5}{12} = \frac{1}{8} + \frac{5}{12} = \frac{3}{24} + \frac{10}{24} = \frac{13}{24}$ 4) $3,25 - 2 \frac{9}{14} = 3 \frac{1}{4} - 2 \frac{9}{14} = 3 \frac{7}{28} - 2 \frac{18}{28} = 2 \frac{35}{28} - 2 \frac{18}{28} = \frac{17}{28}$