-0.04x^2+6x-200=0

Solution for -0.04x^2+6x-200=0 equation:

-0.04x^2+6x-200=0

a = -0.04; b = 6; c = -200;
Δ = b2-4ac
Δ = 62-4·(-0.04)·(-200)
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-2}{2*-0.04}=\frac{-8}{-0.08}
=+100
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+2}{2*-0.04}=\frac{-4}{-0.08}
=+50
$