Tìm (x), biết:

a) \(15x + 25 = 100\)

\(15x = 75\)

\(x = 5\)

Vậy \(x = 5\).

b) \[18 - \left( {x + 14} \right)\,\,{\rm{:}}\,\,{\rm{3  =  27}}\]

\(\left( {x + 14} \right):3 =  - 9\)

\(x + 14 =  - 27\)

\(x =  - 41\)

Vậy \(x =  - 41\).

c) \({2^{x + 3}}{.2^2} = {2^2}.3 + 52\)

\({2^{x + 5}} = 4.3 + 52\)

\({2^{x + 5}} = 64 = {2^6}\)

Suy ra \(x + 5 = 6\)

\(x = 1\)

Vậy \(x = 1\).