(6s+12)(6s-18)=0

Solution for (6s+12)(6s-18)=0 equation:

(6s+12)(6s-18)=0

We multiply parentheses ..

(+36s^2-108s+72s-216)=0

We get rid of parentheses

36s^2-108s+72s-216=0

We add all the numbers together, and all the variables

36s^2-36s-216=0

a = 36; b = -36; c = -216;
Δ = b2-4ac
Δ = -362-4·36·(-216)
Δ = 32400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{32400}=180$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-180}{2*36}=\frac{-144}{72}
=-2
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+180}{2*36}=\frac{216}{72}
=3
$