\[m,\ n\ и\ k - действительные\ числа.\]
\[(x - m)(x - n) = k^{2}\]
\[x^{2} - xn - xm + mn - k^{2} = 0\]
\[x^{2} - (n + m)x + \left( mn - k^{2} \right) = 0\]
\[D = (n + m)^{2} - 4\left( mn - k^{2} \right) =\]
\[= n^{2} + 2mn + m^{2} - 4mn + 4k^{2} =\]
\[= \left( n^{2} - 2mn + m^{2} \right) + 4k^{2} =\]
\[= (n - m)^{2} + 4k^{2} \geq 0.\]
\[Ответ:\ \ нет.\]