[tex] {2x}^{2} + 3x - 7 = 0[/tex]
[tex]a = 2[/tex]
[tex]b = 3[/tex]
[tex]c = - 7[/tex]
[tex]\Delta = {b}^{2} - 4ac[/tex]
[tex]\Delta = {3}^{2} - 4 \times 2 \times ( - 7)[/tex]
[tex]\Delta = 9 + 56[/tex]
[tex]\Delta = 65[/tex]
[tex]x_{1,2}=\frac{-b\:\pm\: \sqrt{\Delta} }{2a}[/tex]
[tex]x_{1,2}=\frac{-3\:\pm\:\sqrt{65}}{2\times2}[/tex]
[tex]x_{1,2}=\frac{-3\:\pm\:\sqrt{65}}{4}[/tex]
[tex]x_{1}=\frac{-3 + \sqrt{65}}{4}[/tex]
[tex]x_{2}=\frac{-3 - \sqrt{65}}{4}[/tex]
