Răspuns:
[tex]5 {x}^{2} + 2x - 6 = [/tex]
[tex]delta = {b}^{2} - 4ac = {2}^{2} - 4 \times 5 \times ( - 6) = 4 + 120 = 124 \: = > \sqrt{delta} = 2 \sqrt{31} [/tex]
[tex]5( {x} + \frac{2}{10} ) + \frac{ - 2 \sqrt{31} }{4 \times 5} = [/tex]
[tex]5(x + \frac{1}{5} ) - \frac{ \sqrt{31} }{5} [/tex]
