0=-0.36x^2+39.16x-617.41

Solution for 0=-0.36x^2+39.16x-617.41 equation:

0=-0.36x^2+39.16x-617.41

We move all terms to the left:

0-(-0.36x^2+39.16x-617.41)=0

We add all the numbers together, and all the variables

-(-0.36x^2+39.16x-617.41)=0

We get rid of parentheses

0.36x^2-39.16x+617.41=0

a = 0.36; b = -39.16; c = +617.41;
Δ = b2-4ac
Δ = -39.162-4·0.36·617.41
Δ = 644.4352
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{-(-39.16)-\sqrt{644.4352}}{2*0.36}=\frac{39.16-\sqrt{644.4352}}{0.72}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-39.16)+\sqrt{644.4352}}{2*0.36}=\frac{39.16+\sqrt{644.4352}}{0.72}
$