\[\boxed{\mathbf{141.}}\]
\[1)\ x - 3 = 0\ \ и\ \ x^{2} - 5x + 6 = 0\]
\[Решим\ первое\ уравнение:\]
\[x - 3 = 0;\]
\[x = 3.\]
\[Решим\ второе\ уравнение:\]
\[x^{2} - 5x + 6 = 0;\]
\[D = 5^{2} - 4 \bullet 6 = 25 - 24 = 1\]
\[x_{1} = \frac{5 - 1}{2} = 2;\text{\ \ }x_{2} = \frac{5 + 1}{2} = 3.\]
\[Ответ:\ \ второе.\]
\[2)\ \frac{x^{2} - 3x + 2}{x - 1} = 0\ \ и\ \ \]
\[x^{2} - 3x + 2 = 0\]
\[Решим\ второе\ уравнение:\]
\[x^{2} - 3x + 2 = 0\]
\[D = 3^{2} - 4 \bullet 2 = 9 - 8 = 1\]
\[x_{1} = \frac{3 - 1}{2} = 1;\text{\ \ }x_{2} = \frac{3 + 1}{2} = 2.\]
\[Решим\ первое\ уравнение:\]
\[\frac{x^{2} - 3x + 2}{x - 1} = 0\]
\[\frac{(x - 1)(x - 2)}{x - 1} = 0\]
\[x - 2 = 0\]
\[x = 2.\]
\[Ответ:\ \ второе.\]