\[\boxed{\mathbf{591}.}\]
\[1)\ x - 2 = 0\ \ и\]
\[\text{\ \ }x^{2} - 5x + 6 = 0;\]
\[Решим\ первое\ уравнение:\]
\[x - 2 = 0;\]
\[x = 2.\]
\[Решим\ второе\ уравнение:\]
\[x^{2} - 5x + 6 = 0;\]
\[D = 5^{2} - 4 \bullet 6 = 25 - 24 = 1\]
\[x_{1} = \frac{5 - 1}{2} = 2\ \ и\]
\[\text{\ \ }x_{2} = \frac{5 + 1}{2} = 3;\]
\[Ответ:\ \ второе.\]
\[2)\ \frac{x^{2} - 5x + 4}{x - 1} = 0\ \ и\]
\[\text{\ \ }x^{2} - 5x + 4 = 0;\]
\[Решим\ второе\ уравнение:\]
\[x^{2} - 5x + 4 = 0\]
\[D = 25 - 16 = 9\]
\[x_{1} = \frac{5 + 3}{2} = 4;\text{\ \ }\]
\[x_{2} = \frac{5 - 3}{2} = 1.\]
\[Решим\ первое\ уравнение:\]
\[\frac{(x - 4)(x - 1)}{x - 1} = 0\]
\[x - 4 = 0\]
\[x = 4.\]
\[Ответ:\ \ второе.\]