X^2-5.75*x-5.75=0

Solution for X^2-5.75*x-5.75=0 equation:

X^2-5.75X-5.75=0

a = 1; b = -5.75; c = -5.75;
Δ = b2-4ac
Δ = -5.752-4·1·(-5.75)
Δ = 56.0625
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{-(-5.75)-\sqrt{56.0625}}{2*1}=\frac{5.75-\sqrt{56.0625}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5.75)+\sqrt{56.0625}}{2*1}=\frac{5.75+\sqrt{56.0625}}{2}
$