1. Найдите значение выражения: 1) 5/12 + 1/8; 2) −3/7 − 9/14; 3) 4/9 : (−8/15); 4) 4 − 2 3/5; 5) −2,5 · (−1,4); 6) 24 : (−0,4).

1. \(\frac{5}{12}+\frac{1}{8}=\frac{10}{24}+\frac{3}{24}=\frac{13}{24}\).
2. \(-\frac{3}{7}-\frac{9}{14}=-\frac{6}{14}-\frac{9}{14}=-\frac{15}{14}=-1\frac{1}{14}\).
3. \(\frac{4}{9}:\left(-\frac{8}{15}\right)=\frac{4}{9}\cdot\left(-\frac{15}{8}\right)=-\frac{5}{6}\).
4. \(4-2\frac{3}{5}=4-\frac{13}{5}=\frac{7}{5}=1\frac{2}{5}\).
5. \(-2.5\cdot(-1.4)=3.5\).
6. \(24:(-0.4)=-60\).

Ответ: 1) \(\frac{13}{24}\); 2) \(-1\frac{1}{14}\); 3) \(-\frac{5}{6}\); 4) \(1\frac{2}{5}\); 5) \(3.5\); 6) \(-60\).