-.0005x^2+1.8x-500=0

Solution for -.0005x^2+1.8x-500=0 equation:

-.0005x^2+1.8x-500=0

We add all the numbers together, and all the variables

-0.0005x^2+1.8x-500=0

a = -0.0005; b = 1.8; c = -500;
Δ = b2-4ac
Δ = 1.82-4·(-0.0005)·(-500)
Δ = 2.24
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{-(1.8)-\sqrt{2.24}}{2*-0.0005}=\frac{-1.8-\sqrt{2.24}}{-0.001}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.8)+\sqrt{2.24}}{2*-0.0005}=\frac{-1.8+\sqrt{2.24}}{-0.001}
$