x^2-0.17x-0.17=0

Solution for x^2-0.17x-0.17=0 equation:

x^2-0.17x-0.17=0

a = 1; b = -0.17; c = -0.17;
Δ = b2-4ac
Δ = -0.172-4·1·(-0.17)
Δ = 0.7089
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{-(-0.17)-\sqrt{0.7089}}{2*1}=\frac{0.17-\sqrt{0.7089}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.17)+\sqrt{0.7089}}{2*1}=\frac{0.17+\sqrt{0.7089}}{2}
$