[tex]6 {x }^{2} + x - 7 = 0 \\ d = 1 {}^{2} - 4 \times 6 \times ( - 7) = \\ 1 + 168 = 169 \\ x_{1} = \frac{ - 1 + 13}{2 \times 6} = \frac{12}{12} = 1 \\ x_{2} = \frac{ - 1 - 13}{2 \times 6} = - \frac{14}{12} = \\ - \frac{7}{6} = - 1 \frac{1}{6} [/tex]

[tex]8 {x}^{2} - 2x + 1 = 0 \\ d = ( - 2) {}^{2} - 4 \times 8 \times 1 = \\ 4 - 32 = - 28 \\ d < 0[/tex]

нет корней