x2-2x-39600=0

Solution for x2-2x-39600=0 equation:

x2-2x-39600=0

We add all the numbers together, and all the variables

x^2-2x-39600=0

a = 1; b = -2; c = -39600;
Δ = b2-4ac
Δ = -22-4·1·(-39600)
Δ = 158404
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{158404}=398$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-398}{2*1}=\frac{-396}{2}
=-198
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+398}{2*1}=\frac{400}{2}
=200
$