x=(x+8)(x+2)

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

x=(x+8)(x+2)

We move all terms to the left:

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

We multiply parentheses ..

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


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

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

We get rid of parentheses

x^2+2x+8x+16

We add all the numbers together, and all the variables

x^2+10x+16

Back to the equation:

-(x^2+10x+16)


We add all the numbers together, and all the variables

x-(x^2+10x+16)=0

We get rid of parentheses

-x^2+x-10x-16=0

We add all the numbers together, and all the variables

-1x^2-9x-16=0

a = -1; b = -9; c = -16;
Δ = b2-4ac
Δ = -92-4·(-1)·(-16)
Δ = 17
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-\sqrt{17}}{2*-1}=\frac{9-\sqrt{17}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+\sqrt{17}}{2*-1}=\frac{9+\sqrt{17}}{-2}
$