x2-2(-3+3)x+9+3=0

Solution for x2-2(-3+3)x+9+3=0 equation:

x2-2(-3+3)x+9+3=0

We add all the numbers together, and all the variables

x2-20x+9+3=0

We add all the numbers together, and all the variables

x^2-20x+12=0

a = 1; b = -20; c = +12;
Δ = b2-4ac
Δ = -202-4·1·12
Δ = 352
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:

$\sqrt{\Delta}=\sqrt{352}=\sqrt{16*22}=\sqrt{16}*\sqrt{22}=4\sqrt{22}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-4\sqrt{22}}{2*1}=\frac{20-4\sqrt{22}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+4\sqrt{22}}{2*1}=\frac{20+4\sqrt{22}}{2}
$