1 5.15--6- 10 10 4

5. $$15\frac{1}{10}-6\frac{4}{10} = (15-6) + (\frac{1}{10} - \frac{4}{10}) = 9 - \frac{3}{10} = 8 + 1 - \frac{3}{10} = 8 + \frac{10}{10} - \frac{3}{10} = 8\frac{7}{10}$$.

Ответ: $$8\frac{7}{10}$$