x^2+0.39x-0.085=0

Solution for x^2+0.39x-0.085=0 equation:

x^2+0.39x-0.085=0

a = 1; b = 0.39; c = -0.085;
Δ = b2-4ac
Δ = 0.392-4·1·(-0.085)
Δ = 0.4921
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{-(0.39)-\sqrt{0.4921}}{2*1}=\frac{-0.39-\sqrt{0.4921}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.39)+\sqrt{0.4921}}{2*1}=\frac{-0.39+\sqrt{0.4921}}{2}
$