[tex]x^{2} + 9x - 4 = 0[/tex]
[tex]x = \frac{-9 +/- \sqrt{9^{2} - 4(1)(-4)}}{2(1)} [/tex]
[tex]x = \frac{-9 +/- \sqrt{81 + 16}}{2} [/tex]
[tex]x = \frac{-9 +/- \sqrt{97}}{2} [/tex]
[tex]x = \frac{-9 +/- 9.848857802}{2} [/tex]
[tex]x = \frac{-9 + 9.848857802}{2} [/tex] [tex]x = \frac{-9 - 9.848857802}{2}[/tex]
[tex]x = \frac{0.848857802}{2} [/tex] [tex]x = \frac{-18.848857802}{2} [/tex]
[tex]x = 0.424428901[/tex] [tex]x = -9.424428901[/tex]
