[tex]2x^2 - 3x - 4 = 0 \\ x= \frac{-b \pm \sqrt{ b^{2} -4ac} }{2a} \\ = \frac{-(-3) \pm \sqrt{ (-3)^{2} -4 \times2 \times (-4)} }{2 \times 2} \\ = \frac{3 \pm \sqrt{ 9 +32} }{4} \\ = \frac{3 \pm \sqrt{41} }{4} \\ = \frac{3 + \sqrt{41} }{4} \ or \ \frac{3 - \sqrt{41} }{4} \\ =2.35 \ or \ -0.85[/tex]
