x2+20x-8=0

Solution for x2+20x-8=0 equation:

x2+20x-8=0

We add all the numbers together, and all the variables

x^2+20x-8=0

a = 1; b = 20; c = -8;
Δ = b2-4ac
Δ = 202-4·1·(-8)
Δ = 432
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{432}=\sqrt{144*3}=\sqrt{144}*\sqrt{3}=12\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-12\sqrt{3}}{2*1}=\frac{-20-12\sqrt{3}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+12\sqrt{3}}{2*1}=\frac{-20+12\sqrt{3}}{2}
$