3x(4x+4)=360

Solution for 3x(4x+4)=360 equation:

3x(4x+4)=360

We move all terms to the left:

3x(4x+4)-(360)=0

We multiply parentheses

12x^2+12x-360=0

a = 12; b = 12; c = -360;
Δ = b2-4ac
Δ = 122-4·12·(-360)
Δ = 17424
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{17424}=132$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(12)-132}{2*12}=\frac{-144}{24}
=-6
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(12)+132}{2*12}=\frac{120}{24}
=5
$