0=0.005x^2-0.319x+4

Solution for 0=0.005x^2-0.319x+4 equation:

0=0.005x^2-0.319x+4

We move all terms to the left:

0-(0.005x^2-0.319x+4)=0

We add all the numbers together, and all the variables

-(0.005x^2-0.319x+4)=0

We get rid of parentheses

-0.005x^2+0.319x-4=0

a = -0.005; b = 0.319; c = -4;
Δ = b2-4ac
Δ = 0.3192-4·(-0.005)·(-4)
Δ = 0.021761
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{-(0.319)-\sqrt{0.021761}}{2*-0.005}=\frac{-0.319-\sqrt{0.021761}}{-0.01}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.319)+\sqrt{0.021761}}{2*-0.005}=\frac{-0.319+\sqrt{0.021761}}{-0.01}
$