12. Найдите значение выражения: 1) (−4/15 + 5/9) : (−26/45); 2) −12 : (−2 1/13) + 1 1/4 : (−15/46).

1. \(\left(-\frac{4}{15}+\frac{5}{9}\right):\left(-\frac{26}{45}\right)=\left(-\frac{12}{45}+\frac{25}{45}\right):\left(-\frac{26}{45}\right)=\frac{13}{45}\cdot\left(-\frac{45}{26}\right)=-\frac12\).
2. \(-12:\left(-2\frac{1}{13}\right)+1\frac14:\left(-\frac{15}{46}\right)=(-12):\left(-\frac{27}{13}\right)+\frac54:\left(-\frac{15}{46}\right)=\frac{52}{9}-\frac{23}{6}=\frac{35}{18}\).

Ответ: 1) −1/2; 2) 35/18.