x*x-6x-2*2+2*6=7

Solution for x*x-6x-2*2+2*6=7 equation:

x*x-6x-2*2+2*6=7

We move all terms to the left:

x*x-6x-2*2+2*6-(7)=0

determiningTheFunctionDomain
x*x-6x-7-2*2+2*6=0

We add all the numbers together, and all the variables

-6x+x*x+1=0

Wy multiply elements

x^2-6x+1=0

a = 1; b = -6; c = +1;
Δ = b2-4ac
Δ = -62-4·1·1
Δ = 32
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:

$\sqrt{\Delta}=\sqrt{32}=\sqrt{16*2}=\sqrt{16}*\sqrt{2}=4\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-4\sqrt{2}}{2*1}=\frac{6-4\sqrt{2}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+4\sqrt{2}}{2*1}=\frac{6+4\sqrt{2}}{2}
$