How do you solve  5x + 4x^2 – 4 = 0 using the quadratic formula?

$D = {d}^{2} = {b}^{2} - 4 a c = 25 + 64 = 89 - \to d = \pm \sqrt{89}$
$x = \left(- \frac{b}{2 a}\right) \pm \frac{d}{2 a} = - \frac{4}{10} \pm \frac{\sqrt{89}}{10}$