-8/9-1 7/27=

$$- \frac{8}{9} - 1 \frac{7}{27} = - \frac{8}{9} - \frac{34}{27} = - \frac{8 \cdot 3}{9 \cdot 3} - \frac{34}{27} = - \frac{24}{27} - \frac{34}{27} = - \frac{58}{27} = -2 \frac{4}{27}$$

Ответ: $$-2 \frac{4}{27}$$