-2x^2+0,8x=0

Solution for -2x^2+0,8x=0 equation:

-2x^2+0.8x=0

a = -2; b = 0.8; c = 0;
Δ = b2-4ac
Δ = 0.82-4·(-2)·0
Δ = 0.64
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{0.64}}{2*-2}=\frac{-0.8-\sqrt{0.64}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.8)+\sqrt{0.64}}{2*-2}=\frac{-0.8+\sqrt{0.64}}{-4}
$