-(w+6)(w+3)=0

Solution for -(w+6)(w+3)=0 equation:

-(w+6)(w+3)=0

We multiply parentheses ..

-(+w^2+3w+6w+18)=0

We get rid of parentheses

-w^2-3w-6w-18=0

We add all the numbers together, and all the variables

-1w^2-9w-18=0

a = -1; b = -9; c = -18;
Δ = b2-4ac
Δ = -92-4·(-1)·(-18)
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9}=3$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-3}{2*-1}=\frac{6}{-2}
=-3
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+3}{2*-1}=\frac{12}{-2}
=-6
$