Решим данные квадратные уравнения.
а) $$x^2 - 5x + 6 = 0$$
По теореме Виета:
$$x_1 + x_2 = 5$$
$$x_1 \cdot x_2 = 6$$
$$x_1 = 2$$, $$x_2 = 3$$
$$6x^2 - 5x + 1 = 0$$
$$D = (-5)^2 - 4 \cdot 6 \cdot 1 = 25 - 24 = 1$$
$$x_1 = \frac{5 + \sqrt{1}}{2 \cdot 6} = \frac{5 + 1}{12} = \frac{6}{12} = \frac{1}{2}$$
$$x_2 = \frac{5 - \sqrt{1}}{2 \cdot 6} = \frac{5 - 1}{12} = \frac{4}{12} = \frac{1}{3}$$
б) $$2x^2 - 13x + 6 = 0$$
$$D = (-13)^2 - 4 \cdot 2 \cdot 6 = 169 - 48 = 121$$
$$x_1 = \frac{13 + \sqrt{121}}{2 \cdot 2} = \frac{13 + 11}{4} = \frac{24}{4} = 6$$
$$x_2 = \frac{13 - \sqrt{121}}{2 \cdot 2} = \frac{13 - 11}{4} = \frac{2}{4} = \frac{1}{2}$$
$$6x^2 - 13x + 2 = 0$$
$$D = (-13)^2 - 4 \cdot 6 \cdot 2 = 169 - 48 = 121$$
$$x_1 = \frac{13 + \sqrt{121}}{2 \cdot 6} = \frac{13 + 11}{12} = \frac{24}{12} = 2$$
$$x_2 = \frac{13 - \sqrt{121}}{2 \cdot 6} = \frac{13 - 11}{12} = \frac{2}{12} = \frac{1}{6}$$
Ответ: а) $$x_1 = 2, x_2 = 3$$ и $$x_1 = \frac{1}{2}, x_2 = \frac{1}{3}$$; б) $$x_1 = 6, x_2 = \frac{1}{2}$$ и $$x_1 = 2, x_2 = \frac{1}{6}$$