Ответ:

  1. \[2\frac{1}{2}\left(\frac{2}{15}-3\frac{5}{6}\right)+\frac14=\frac52\left(\frac{2}{15}-\frac{23}{6}\right)+\frac14=\frac52\cdot\left(-\frac{111}{30}\right)+\frac14=-\frac{37}{4}+\frac14=-9.\]
  2. \[-1\frac17\left(\frac45+\frac{19}{20}\right)\left(6\frac56+4\frac23\right)=-\frac87\cdot\frac{35}{20}\cdot\frac{69}{6}=-\frac87\cdot\frac74\cdot\frac{23}{2}=-23.\]

Жауабы: 1) −9; 2) −23.