Ответ:

[tex] {x}^{2} + 2x - 8 = 0 \\ d = 4 + 4 \times 8 = 36 \\ x1 = \frac{ - 2 + 6}{2} = 2 \\ x2 = \frac{ - 2 - 6}{2} = - 4 \\ \\ 3 {x}^{2} + 7x + 4 = 0 \\ d = 49 - 4 \times 3 \times 4 = 1 \\ x1 = \frac{ - 7 - 1}{6} = - \frac{8}{6} = - \frac{4}{3} \\ x2 = \frac{ - 7 + 1}{6} = - 1[/tex]