Ответ:
\(23 + x = 56\), \(x = 56 - 23 = 33\).
\(20 : a = 4\), \(a = 20 : 4 = 5\).
\(18 - a = 43\), \(a = 18 - 43 = -25\).
\(a : 4 = 25\), \(a = 25 \cdot 4 = 100\).
Ответ: \(x = 33\), \(a = 5\), \(a = -25\), \(a = 100\).
\(23 + x = 56\), \(x = 56 - 23 = 33\).
\(20 : a = 4\), \(a = 20 : 4 = 5\).
\(18 - a = 43\), \(a = 18 - 43 = -25\).
\(a : 4 = 25\), \(a = 25 \cdot 4 = 100\).
Ответ: \(x = 33\), \(a = 5\), \(a = -25\), \(a = 100\).