x^2-200x+2100=0

Solution for x^2-200x+2100=0 equation:

x^2-200x+2100=0

a = 1; b = -200; c = +2100;
Δ = b2-4ac
Δ = -2002-4·1·2100
Δ = 31600
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:

$\sqrt{\Delta}=\sqrt{31600}=\sqrt{400*79}=\sqrt{400}*\sqrt{79}=20\sqrt{79}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-200)-20\sqrt{79}}{2*1}=\frac{200-20\sqrt{79}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-200)+20\sqrt{79}}{2*1}=\frac{200+20\sqrt{79}}{2}
$