-0.01x^2+0.8x+6.3=0

Solution for -0.01x^2+0.8x+6.3=0 equation:

-0.01x^2+0.8x+6.3=0

a = -0.01; b = 0.8; c = +6.3;
Δ = b2-4ac
Δ = 0.82-4·(-0.01)·6.3
Δ = 0.892
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0.8)-\sqrt{0.892}}{2*-0.01}=\frac{-0.8-\sqrt{0.892}}{-0.02}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.8)+\sqrt{0.892}}{2*-0.01}=\frac{-0.8+\sqrt{0.892}}{-0.02}
$