Answer
$x\displaystyle \approx0.259$ or $x\displaystyle \approx-0.248$
Work Step by Step
We use the quadratic formula with $a=1$, $b=-0.011$, and $c=-0.064$:
$x^{2}-0.011x-0.064=0$
$x=\frac{-(-0.011)\pm\sqrt{(-0.011)^{2}-4(1)(-0.064)}}{2(1)}=\frac{0.011\pm\sqrt{0.000121+0.256}}{2}\approx\frac{0.011\pm 0.506}{2}$
So we have:
$x\displaystyle \approx\frac{0.011+0.506}{2}=0.259$
Or:
$x\displaystyle \approx\frac{0.011-0.506}{2}=-0.248$