12=(8-x)x

Solution for 12=(8-x)x equation:

12=(8-x)x

We move all terms to the left:

12-((8-x)x)=0

We add all the numbers together, and all the variables

-((-1x+8)x)+12=0


We calculate terms in parentheses: -((-1x+8)x), so:

(-1x+8)x

We multiply parentheses

-1x^2+8x

Back to the equation:

-(-1x^2+8x)


We get rid of parentheses

1x^2-8x+12=0

We add all the numbers together, and all the variables

x^2-8x+12=0

a = 1; b = -8; c = +12;
Δ = b2-4ac
Δ = -82-4·1·12
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-4}{2*1}=\frac{4}{2}
=2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+4}{2*1}=\frac{12}{2}
=6
$