![image](https://tex.z-dn.net/?f=3+%7Bx%7D%5E%7B2%7D++-+4x+-+7+++%3D+0%5C%5C+d+%3D+16+%2B+4+%5Ctimes+3+%5Ctimes+7+%3D+16+%2B+84+%3D+100+%3E+0+%5C%5C+x1+%3D++%5Cfrac%7B4+%2B+10%7D%7B6%7D++%3D++%5Cfrac%7B14%7D%7B6%7D++%3D++%5Cfrac%7B7%7D%7B3%7D++%5C%5C+x2+%3D++%5Cfrac%7B4+-+10%7D%7B6%7D++%3D++%5Cfrac%7B+-+6%7D%7B6%7D++%3D++-+1+)
0 \\ x1 = \frac{4 + 10}{6} = \frac{14}{6} = \frac{7}{3} \\ x2 = \frac{4 - 10}{6} = \frac{ - 6}{6} = - 1 " alt="3 {x}^{2} - 4x - 7 = 0\\ d = 16 + 4 \times 3 \times 7 = 16 + 84 = 100 > 0 \\ x1 = \frac{4 + 10}{6} = \frac{14}{6} = \frac{7}{3} \\ x2 = \frac{4 - 10}{6} = \frac{ - 6}{6} = - 1 " align="absmiddle" class="latex-formula">