0.25x^2-0.6x-1=0

Solution for 0.25x^2-0.6x-1=0 equation:

0.25x^2-0.6x-1=0

a = 0.25; b = -0.6; c = -1;
Δ = b2-4ac
Δ = -0.62-4·0.25·(-1)
Δ = 1.36
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{-(-0.6)-\sqrt{1.36}}{2*0.25}=\frac{0.6-\sqrt{1.36}}{0.5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.6)+\sqrt{1.36}}{2*0.25}=\frac{0.6+\sqrt{1.36}}{0.5}
$