y^2-201y+9900=0

Solution for y^2-201y+9900=0 equation:

y^2-201y+9900=0

a = 1; b = -201; c = +9900;
Δ = b2-4ac
Δ = -2012-4·1·9900
Δ = 801
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{801}=\sqrt{9*89}=\sqrt{9}*\sqrt{89}=3\sqrt{89}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-201)-3\sqrt{89}}{2*1}=\frac{201-3\sqrt{89}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-201)+3\sqrt{89}}{2*1}=\frac{201+3\sqrt{89}}{2}
$