2. Выполните действия: 1) -12,6 0,6 + 4,8 · (−1,3); 2) (4,3-5) (-5,16 + 5,08); 3) 5/7·(-1 10/11) - (-2 5/11)·5/54; 4) (5 1/4-6 1/6) (3 1/4-0,55).

Ответ: смотри решение ниже

1. \[ -12.6 \cdot 0.6 + 4.8 \cdot (-1.3) = -7.56 - 6.24 = -13.8 \]

2. \[ (4.3 - 5) \cdot (-5.16 + 5.08) = (-0.7) \cdot (-0.08) = 0.056 \]

3. \[ \frac{5}{7} \cdot (-1\frac{10}{11}) - (-2\frac{5}{11}) \cdot \frac{5}{54} = \frac{5}{7} \cdot (-\frac{21}{11}) - (-\frac{27}{11}) \cdot \frac{5}{54} = \frac{5}{7} \cdot (-\frac{21}{11}) + \frac{27}{11} \cdot \frac{5}{54} = -\frac{5 \cdot 21}{7 \cdot 11} + \frac{27 \cdot 5}{11 \cdot 54} = -\frac{5 \cdot 3}{11} + \frac{1 \cdot 5}{11 \cdot 2} = -\frac{15}{11} + \frac{5}{22} = -\frac{30}{22} + \frac{5}{22} = -\frac{25}{22} = -1\frac{3}{22} \]

4. \[ (5\frac{1}{4} - 6\frac{1}{6}) \cdot (3\frac{1}{4} - 0.55) = (\frac{21}{4} - \frac{37}{6}) \cdot (\frac{13}{4} - \frac{55}{100}) = (\frac{63}{12} - \frac{74}{12}) \cdot (\frac{13}{4} - \frac{11}{20}) = -\frac{11}{12} \cdot (\frac{65}{20} - \frac{11}{20}) = -\frac{11}{12} \cdot \frac{54}{20} = -\frac{11}{12} \cdot \frac{27}{10} = -\frac{11 \cdot 9}{4 \cdot 10} = -\frac{99}{40} = -2\frac{19}{40} \]

Ответ: 1) -13.8; 2) 0.056; 3) -1 3/22; 4) -2 19/40.