\[x^{2} - (2k - 2)x - 4k = 0\]
\[D =\]
\[= \left( - (2k - 2) \right)^{2} - 4 \cdot 1 \cdot ( - 4k) =\]
\[= (2k - 2)^{2} + 16k =\]
\[4k^{2} - 8k + 4 + 16k =\]
\[= 4k^{2} + 8k + 4 =\]
\[= 4 \bullet \left( k^{2} + 2k + 1 \right) =\]
\[= 4{\bullet (k + 1)}^{2}\]
\[k
eq - 1 \Longrightarrow D > 0 \Longrightarrow\]
\[x_{1} = \frac{2k - 2 + 2 \bullet (k + 1)}{2} =\]
\[= \frac{2k - 2 + 2k + 2}{2} = \frac{4k}{2} = 2k\]
\[x_{2} = \frac{2k - 2 - 2 \bullet (k + 1)}{2} =\]
\[= \frac{2k - 2 - 2k - 2}{2} = \frac{- 4}{2} = - 2\]
\[k = - 1 \Longrightarrow D = 0 \Longrightarrow\]
\[x = \frac{2k - 2}{2} = k - 1 = - 1 - 1 =\]
\[= - 2.\]
\[Ответ:x = 2k\ и\ x = - 2\ при\]
\[\ k
eq - 1;\ \ \ \]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ x = - 2\ при\ k = - 1.\]