Tìm (x), biết:

a) \(x - 12 =  - 37\)

\(x =  - 37 + 12\)

\(x =  - 25\).

Vậy \(x =  - 25\).

b) \( - 152 - \left( {3x + 1} \right) = 54\)

\[3x + 1 =  - 152 - 54\]

\[3x + 1 =  - 206\]

\(3x =  - 207\)

\(x =  - 69\)

Vậy \(x =  - 69\).

c) \({2^x} + {2^{x + 3}} = 144\)

\({2^x} + {2^x}{.2^3} = 144\)

\({2^x}.\left( {1 + {2^3}} \right) = 144\)

\({2^x}.9 = 144\)

\({2^x} = 144 : 9\)

\({2^x} = 16\)

\({2^x} = {2^4}\)

Suy ra \(x = 4\).

Vậy \(x = 4\).