Ответ:

Переводим дроби в десятичные или приводим дроби к общему знаменателю, чтобы выполнить действие.

  1. \(\frac{1}{2}-0.4=0.5-0.4=0.1\).
  2. \(0.2+\frac{2}{25}=0.2+0.08=0.28\).
  3. \(0.3+\frac{2}{5}=0.3+0.4=0.7\).
  4. \(\frac{9}{20}-0.45=0.45-0.45=0\).
  5. \(\frac{1}{6}-0.1=\frac{5}{30}-\frac{3}{30}=\frac{1}{15}\).
  6. \(0.05+\frac{11}{20}=0.05+0.55=0.6\).
  7. \(\frac{1}{10}-\frac{1}{12}=\frac{6}{60}-\frac{5}{60}=\frac{1}{60}\).
  8. \(\frac{9}{25}-0.2=0.36-0.2=0.16\).
  9. \(\frac{3}{4}+0.1=0.75+0.1=0.85\).
  10. \(0.25-\frac{1}{20}=0.25-0.05=0.2\).
  11. \(\frac{1}{9}-\frac{1}{10}=\frac{10}{90}-\frac{9}{90}=\frac{1}{90}\).
  12. \(\frac{3}{20}+0.15=0.15+0.15=0.3\).
  13. \(0.9-\frac{3}{5}=0.9-0.6=0.3\).
  14. \(\frac{7}{50}+0.6=0.14+0.6=0.74\).
  15. \(0.5-\frac{11}{25}=0.5-0.44=0.06\).