Tìm số nguyên \(x\), biết:

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

e) \( - 138 \cdot 2 + 125 \cdot 3 - \left( { - 138 \cdot 2} \right) + 75 \cdot 3\)

\( = \left[ { - 138 \cdot 2 - \left( { - 138 \cdot 2} \right)} \right] + \left( {125 \cdot 3 + 75 \cdot 3} \right)\)

\( = 0 + 3 \cdot \left( {125 + 75} \right)\)

\( = 0 + 3 \cdot 200\)

b) \[\left( { - 25} \right) \cdot 8 \cdot \left( { - 125} \right) \cdot 3 \cdot \left( { - 4} \right)\]

\( = \left[ {\left( { - 25} \right) \cdot \left( { - 4} \right)} \right] \cdot \left[ {8 \cdot \left( { - 125} \right)} \right] \cdot 3\)

\[ = 100 \cdot \left( { - 1\,\,000} \right) \cdot 3\]