9.2. Решите уравнение 2 · (5x − 7) = −2. Аналоги: 9.2.1. 5 · (x + 4) = −9; 9.2.2. 10 · (x − 9) = 7; 9.2.3. 5 · (x − 6) = 2; 9.2.4. 4 · (x − 8) = −5; 9.2.5. 4 · (x − 6) = 5.

Раскрываем скобки, приводим подобные слагаемые и находим неизвестное.

1. Основное уравнение: \(2(5x-7)=-2\); \(10x-14=-2\); \(10x=12\); \(x=\frac{6}{5}\).
2. 9.2.1: \(5(x+4)=-9\); \(x+4=-\frac{9}{5}\); \(x=-\frac{29}{5}\).
3. 9.2.2: \(10(x-9)=7\); \(x-9=\frac{7}{10}\); \(x=\frac{97}{10}\).
4. 9.2.3: \(5(x-6)=2\); \(x-6=\frac{2}{5}\); \(x=\frac{32}{5}\).
5. 9.2.4: \(4(x-8)=-5\); \(x-8=-\frac{5}{4}\); \(x=\frac{27}{4}\).
6. 9.2.5: \(4(x-6)=5\); \(x-6=\frac{5}{4}\); \(x=\frac{29}{4}\).

Ответ: 9.2: \(x=\frac{6}{5}\); 9.2.1: \(x=-\frac{29}{5}\); 9.2.2: \(x=\frac{97}{10}\); 9.2.3: \(x=\frac{32}{5}\); 9.2.4: \(x=\frac{27}{4}\); 9.2.5: \(x=\frac{29}{4}\).