x2+6x+6x+20=8

Solution for x2+6x+6x+20=8 equation:

x2+6x+6x+20=8

We move all terms to the left:

x2+6x+6x+20-(8)=0

We add all the numbers together, and all the variables

x^2+12x+12=0

a = 1; b = 12; c = +12;
Δ = b2-4ac
Δ = 122-4·1·12
Δ = 96
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:

$\sqrt{\Delta}=\sqrt{96}=\sqrt{16*6}=\sqrt{16}*\sqrt{6}=4\sqrt{6}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(12)-4\sqrt{6}}{2*1}=\frac{-12-4\sqrt{6}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(12)+4\sqrt{6}}{2*1}=\frac{-12+4\sqrt{6}}{2}
$