36x(x+6)=128

Solution for 36x(x+6)=128 equation:

36x(x+6)=128

We move all terms to the left:

36x(x+6)-(128)=0

We multiply parentheses

36x^2+216x-128=0

a = 36; b = 216; c = -128;
Δ = b2-4ac
Δ = 2162-4·36·(-128)
Δ = 65088
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:

$\sqrt{\Delta}=\sqrt{65088}=\sqrt{576*113}=\sqrt{576}*\sqrt{113}=24\sqrt{113}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(216)-24\sqrt{113}}{2*36}=\frac{-216-24\sqrt{113}}{72}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(216)+24\sqrt{113}}{2*36}=\frac{-216+24\sqrt{113}}{72}
$