x^2=0.0004-0.004x

Solution for x^2=0.0004-0.004x equation:

x^2=0.0004-0.004x

We move all terms to the left:

x^2-(0.0004-0.004x)=0

We add all the numbers together, and all the variables

x^2-(-0.004x+0.0004)=0

We get rid of parentheses

x^2+0.004x-0.0004=0

a = 1; b = 0.004; c = -0.0004;
Δ = b2-4ac
Δ = 0.0042-4·1·(-0.0004)
Δ = 0.001616
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{-(0.004)-\sqrt{0.001616}}{2*1}=\frac{-0.004-\sqrt{0.001616}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.004)+\sqrt{0.001616}}{2*1}=\frac{-0.004+\sqrt{0.001616}}{2}
$