solve for x when x^2 + 0.638x - 0.033495 = 0

$x^2+0.638x-0.033495=0\\x = {-0.638 \pm \sqrt{(0.638)^2-4(1)(-0.033495)} \over 2(1)}\\ \; \;=\frac{-0.638\pm 0.541424}{2}\\ \;\;=-0.319\pm0.270712 \\\textbf{x=-0.589712 or x=-0.048288}$