x^2+10x-820=0

Solution for x^2+10x-820=0 equation:

x^2+10x-820=0

a = 1; b = 10; c = -820;
Δ = b2-4ac
Δ = 102-4·1·(-820)
Δ = 3380
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:

$\sqrt{\Delta}=\sqrt{3380}=\sqrt{676*5}=\sqrt{676}*\sqrt{5}=26\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-26\sqrt{5}}{2*1}=\frac{-10-26\sqrt{5}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+26\sqrt{5}}{2*1}=\frac{-10+26\sqrt{5}}{2}
$