6) 8 1/17 - 6/17 =

6) $$\begin{aligned}8\frac{1}{17} - \frac{6}{17} &= 7 + \frac{17}{17} + \frac{1}{17} - \frac{6}{17} = 7 + \frac{18}{17} - \frac{6}{17} = 7\frac{12}{17}\\\\&=\frac{7 \cdot 17 + 12}{17} = \frac{119+12}{17} = \frac{131}{17} = 7\frac{12}{17}\end{aligned}$$

Ответ: 7 12/17