(x+8)(x+8)=36

Solution for (x+8)(x+8)=36 equation:

(x+8)(x+8)=36

We move all terms to the left:

(x+8)(x+8)-(36)=0

We multiply parentheses ..

(+x^2+8x+8x+64)-36=0

We get rid of parentheses

x^2+8x+8x+64-36=0

We add all the numbers together, and all the variables

x^2+16x+28=0

a = 1; b = 16; c = +28;
Δ = b2-4ac
Δ = 162-4·1·28
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-12}{2*1}=\frac{-28}{2}
=-14
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+12}{2*1}=\frac{-4}{2}
=-2
$