0,1x2-0,5x-3,6=0

Solution for 0,1x2-0,5x-3,6=0 equation:

0.1x^2-0.5x-3.6=0

a = 0.1; b = -0.5; c = -3.6;
Δ = b2-4ac
Δ = -0.52-4·0.1·(-3.6)
Δ = 1.69
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{-(-0.5)-\sqrt{1.69}}{2*0.1}=\frac{0.5-\sqrt{1.69}}{0.2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.5)+\sqrt{1.69}}{2*0.1}=\frac{0.5+\sqrt{1.69}}{0.2}
$