25. Вычислите: 6,8 − 5 5/9

\[6.8=\frac{34}{5},\qquad \frac{34}{5}-5\frac{5}{9}=\frac{34}{5}-\frac{50}{9}=\frac{306-250}{45}=\frac{56}{45}=1\frac{11}{45}.\]

Ответ: \(1\frac{11}{45}\).