s^2+9s=220

Solution for s^2+9s=220 equation:

s^2+9s=220

We move all terms to the left:

s^2+9s-(220)=0

a = 1; b = 9; c = -220;
Δ = b2-4ac
Δ = 92-4·1·(-220)
Δ = 961
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{961}=31$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-31}{2*1}=\frac{-40}{2}
=-20
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+31}{2*1}=\frac{22}{2}
=11
$