3(x+2)(x+6)=0

Solution for 3(x+2)(x+6)=0 equation:

3(x+2)(x+6)=0

We multiply parentheses ..

3(+x^2+6x+2x+12)=0

We multiply parentheses

3x^2+18x+6x+36=0

We add all the numbers together, and all the variables

3x^2+24x+36=0

a = 3; b = 24; c = +36;
Δ = b2-4ac
Δ = 242-4·3·36
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(24)-12}{2*3}=\frac{-36}{6}
=-6
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(24)+12}{2*3}=\frac{-12}{6}
=-2
$