9) 12-5+1 -

9) $$\begin{array}{rcl}12\frac{3}{11}-5\frac{6}{11}+1\frac{9}{11}&=&6\frac{8}{11}+1\frac{9}{11}=7\frac{17}{11}=8\frac{6}{11}\end{array}$$

Ответ: $$8\frac{6}{11}$$