17) -11.3 23

$$ -1\frac{1}{2} \cdot \frac{2}{3} = -\frac{1 \cdot 2 + 1}{2} \cdot \frac{2}{3} = -\frac{3}{2} \cdot \frac{2}{3} = -\frac{3 \cdot 2}{2 \cdot 3} = -\frac{6}{6} = -1$$

Ответ: -1