(3x+6)*(3x+6)=36

Solution for (3x+6)*(3x+6)=36 equation:

(3x+6)(3x+6)=36

We move all terms to the left:

(3x+6)(3x+6)-(36)=0

We multiply parentheses ..

(+9x^2+18x+18x+36)-36=0

We get rid of parentheses

9x^2+18x+18x+36-36=0

We add all the numbers together, and all the variables

9x^2+36x=0

a = 9; b = 36; c = 0;
Δ = b2-4ac
Δ = 362-4·9·0
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(36)-36}{2*9}=\frac{-72}{18}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+36}{2*9}=\frac{0}{18}
=0
$