Tìm số nguyên \(x\), biết:

f) \(51 + 2\left( {3x - 5} \right) = 5\).

g) \[26 \cdot \left( {74 - 126} \right) - 74 \cdot \left( {126 + 26} \right)\]

\[ = 26 \cdot 74 - 26 \cdot 126 - 74 \cdot 126 - 74 \cdot 26\]

\[ = \left( {26 \cdot 74 - 74 \cdot 126} \right) - \left( {26 \cdot 126 + 74 \cdot 26} \right)\]

\[ = 74 \cdot \left( {26 - 126} \right) - 26 \cdot \left( {126 + 74} \right)\]

\[ = 74 \cdot \left( { - 100} \right) - 26 \cdot 200\]

j) \[{2^x} + {\rm{ }}{2^{x + 4}} = 544\]

\({2^x} + {2^x} \cdot {2^4} = 544\)

 \({2^x} + {2^x} \cdot 16 = 544\)

\[{2^x} \cdot \left( {1 + 16} \right) = 544\]

\[{2^x} \cdot 17 = 544\]

\[{2^x} = 544:17\]

\[{2^x} = 32\]

\({2^x} = {2^5}\)

Suy ra \(x = 5\).