(6x+3)(6x+3)=9

Solution for (6x+3)(6x+3)=9 equation:

(6x+3)(6x+3)=9

We move all terms to the left:

(6x+3)(6x+3)-(9)=0

We multiply parentheses ..

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

We get rid of parentheses

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

We add all the numbers together, and all the variables

36x^2+36x=0

a = 36; b = 36; c = 0;
Δ = b2-4ac
Δ = 362-4·36·0
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*36}=\frac{-72}{72}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+36}{2*36}=\frac{0}{72}
=0
$