Контрольные задания
Вопрос:Фото задания: Д/З. 12 вар. 1) 11/18 − 2/9; 2) 7 − 6 1/12; 3) 2 5/9 + 5 7/15; 4) 8 9/20 − 4 8/15; 5) 4 · 1/4; 6) 18/79 · 3 1/4; 7) 15/16 :…Фото задания

Ответ:

  1. \(\frac{11}{18}-\frac{2}{9}=\frac{11}{18}-\frac{4}{18}=\frac{7}{18}\).
  2. \(7-6\frac{1}{12}=6\frac{12}{12}-6\frac{1}{12}=\frac{11}{12}\).
  3. \(2\frac{5}{9}+5\frac{7}{15}=\frac{23}{9}+\frac{82}{15}=\frac{115+246}{45}=8\frac{1}{45}\).
  4. \(8\frac{9}{20}-4\frac{8}{15}=\frac{169}{20}-\frac{68}{15}=\frac{507-272}{60}=3\frac{11}{12}\).
  5. \(4\cdot\frac{1}{4}=1\).
  6. \(\frac{18}{79}\cdot3\frac{1}{4}=\frac{18}{79}\cdot\frac{13}{4}=\frac{117}{158}\).
  7. \(\frac{15}{16}:\frac{5}{8}=\frac{15}{16}\cdot\frac{8}{5}=\frac{3}{2}=1\frac{1}{2}\).
  8. \(4\frac{1}{5}:\frac{1}{10}=\frac{21}{5}\cdot10=42\).