Вопрос:

266. Найдите значение выражений: 1) \(\frac{4}{11}+\frac{3}{11}-\frac{5}{11}\); 2) \(\frac{8}{15}-\frac{4}{15}+\frac{1}{15}\); 3) \(2\frac{4}{9}-1\frac{1}{9}+3\frac{5}{9}\); 4) \(7\frac{2}{7}+1\frac{3}{7}-2\frac{1}{7}\).

Ответ:

  1. \[\frac{4}{11}+\frac{3}{11}-\frac{5}{11}=\frac{4+3-5}{11}=\frac{2}{11}.\]
  2. \[\frac{8}{15}-\frac{4}{15}+\frac{1}{15}=\frac{8-4+1}{15}=\frac{5}{15}=\frac{1}{3}.\]
  3. \[2\frac{4}{9}-1\frac{1}{9}+3\frac{5}{9}=\frac{22}{9}-\frac{10}{9}+\frac{32}{9}=\frac{44}{9}=4\frac{8}{9}.\]
  4. \[7\frac{2}{7}+1\frac{3}{7}-2\frac{1}{7}=\frac{51}{7}+\frac{10}{7}-\frac{15}{7}=\frac{46}{7}=6\frac{4}{7}.\]

Ответ: 1) \(\frac{2}{11}\); 2) \(\frac{1}{3}\); 3) \(4\frac{8}{9}\); 4) \(6\frac{4}{7}\).