12-(x*x)=2x+4

Solution for 12-(x*x)=2x+4 equation:

12-(x*x)=2x+4

We move all terms to the left:

12-(x*x)-(2x+4)=0

We add all the numbers together, and all the variables

-(+x*x)-(2x+4)+12=0

We get rid of parentheses

-x*x-2x-4+12=0

We add all the numbers together, and all the variables

-2x-x*x+8=0

Wy multiply elements

-1x^2-2x+8=0

a = -1; b = -2; c = +8;
Δ = b2-4ac
Δ = -22-4·(-1)·8
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-6}{2*-1}=\frac{-4}{-2}
=+2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+6}{2*-1}=\frac{8}{-2}
=-4
$