3(x+6)(x+6)=60

Solution for 3(x+6)(x+6)=60 equation:

3(x+6)(x+6)=60

We move all terms to the left:

3(x+6)(x+6)-(60)=0

We multiply parentheses ..

3(+x^2+6x+6x+36)-60=0

We multiply parentheses

3x^2+18x+18x+108-60=0

We add all the numbers together, and all the variables

3x^2+36x+48=0

a = 3; b = 36; c = +48;
Δ = b2-4ac
Δ = 362-4·3·48
Δ = 720
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{720}=\sqrt{144*5}=\sqrt{144}*\sqrt{5}=12\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(36)-12\sqrt{5}}{2*3}=\frac{-36-12\sqrt{5}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+12\sqrt{5}}{2*3}=\frac{-36+12\sqrt{5}}{6}
$