672=(2x-8)(x+8)

Solution for 672=(2x-8)(x+8) equation:

672=(2x-8)(x+8)

We move all terms to the left:

672-((2x-8)(x+8))=0

We multiply parentheses ..

-((+2x^2+16x-8x-64))+672=0


We calculate terms in parentheses: -((+2x^2+16x-8x-64)), so:

(+2x^2+16x-8x-64)

We get rid of parentheses

2x^2+16x-8x-64

We add all the numbers together, and all the variables

2x^2+8x-64

Back to the equation:

-(2x^2+8x-64)


We get rid of parentheses

-2x^2-8x+64+672=0

We add all the numbers together, and all the variables

-2x^2-8x+736=0

a = -2; b = -8; c = +736;
Δ = b2-4ac
Δ = -82-4·(-2)·736
Δ = 5952
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:

$\sqrt{\Delta}=\sqrt{5952}=\sqrt{64*93}=\sqrt{64}*\sqrt{93}=8\sqrt{93}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-8\sqrt{93}}{2*-2}=\frac{8-8\sqrt{93}}{-4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+8\sqrt{93}}{2*-2}=\frac{8+8\sqrt{93}}{-4}
$