\[1)\ 12 + (x - 3)i\]
\[x - 3 = 1\]
\[x = 4.\]
\[Ответ:\ \ 4.\]
\[2) - 1 + (x + 1)i\]
\[x + 1 = 1\]
\[x = 0.\]
\[Ответ:\ \ 0.\]
\[3)\ \sqrt{2} + (2x - 1)i\]
\[2x - 1 = 1\]
\[2x = 2\]
\[x = 1.\]
\[Ответ:\ \ 1.\]
\[4) - \frac{1}{5} - (3x - 4)i\]
\[- (3x - 4) = 1\]
\[3x - 4 = - 1\]
\[3x = 3\]
\[x = 1.\]
\[Ответ:\ \ 1.\]