x^2-220x+7000=0

Solution for x^2-220x+7000=0 equation:

x^2-220x+7000=0

a = 1; b = -220; c = +7000;
Δ = b2-4ac
Δ = -2202-4·1·7000
Δ = 20400
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:

$\sqrt{\Delta}=\sqrt{20400}=\sqrt{400*51}=\sqrt{400}*\sqrt{51}=20\sqrt{51}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-220)-20\sqrt{51}}{2*1}=\frac{220-20\sqrt{51}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-220)+20\sqrt{51}}{2*1}=\frac{220+20\sqrt{51}}{2}
$