Решение:
Решим каждое уравнение:
- \(2(2a + 1) = 18\)
\(4a + 2 = 18\)
\(4a = 16\)
\(a = 4\).- \(2(x - 6) + x = 18\)
\(2x - 12 + x = 18\)
\(3x = 30\)
\(x = 10\).- \(2(1 - x) + 5 = 7\)
\(2 - 2x + 5 = 7\)
\(7 - 2x = 7\)
\(-2x = 0\)
\(x = 0\).
Ответ: \(a = 4\), \(x = 10\), \(x = 0\).