Решение:
a) \(21z = 0.21\)
\(z = \frac{0.21}{21} = 0.01\)
Ответ: **0,01**
б) \(2.64 : a = 4\)
\(a = \frac{2.64}{4} = 0.66\)
Ответ: **0,66**
в) \(317.8 : (n - 5) = 14\)
\(n - 5 = \frac{317.8}{14} = 22.7\)
\(n = 22.7 + 5 = 27.7\)
Ответ: **27,7**
г) \(38(x + 1.3) = 64.6\)
\(x + 1.3 = \frac{64.6}{38} = 1.7\)
\(x = 1.7 - 1.3 = 0.4\)
Ответ: **0,4**