\[(m - 7)x^{2} + 2(m - 7)x + 3 = 0.\]
\[1)\ D = 4(m - 7)^{2} - 4(m - 7) \bullet 3 < 0\]
\[4(m - 7)(m - 7 - 3) < 0\]
\[(m - 7)(m - 10) < 0\]
\[7 < m < 10.\]
\[2)\ Становится\ линейным:\]
\[m - 7 = 0\]
\[m = 7.\]
\[Ответ:\ \ 7;\ 8;\ 9.\]