x^2+2x-636=0

Solution for x^2+2x-636=0 equation:

x^2+2x-636=0

a = 1; b = 2; c = -636;
Δ = b2-4ac
Δ = 22-4·1·(-636)
Δ = 2548
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:

$\sqrt{\Delta}=\sqrt{2548}=\sqrt{196*13}=\sqrt{196}*\sqrt{13}=14\sqrt{13}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-14\sqrt{13}}{2*1}=\frac{-2-14\sqrt{13}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+14\sqrt{13}}{2*1}=\frac{-2+14\sqrt{13}}{2}
$