(x+8)(x+8)=39

Solution for (x+8)(x+8)=39 equation:

(x+8)(x+8)=39

We move all terms to the left:

(x+8)(x+8)-(39)=0

We multiply parentheses ..

(+x^2+8x+8x+64)-39=0

We get rid of parentheses

x^2+8x+8x+64-39=0

We add all the numbers together, and all the variables

x^2+16x+25=0

a = 1; b = 16; c = +25;
Δ = b2-4ac
Δ = 162-4·1·25
Δ = 156
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:

$\sqrt{\Delta}=\sqrt{156}=\sqrt{4*39}=\sqrt{4}*\sqrt{39}=2\sqrt{39}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-2\sqrt{39}}{2*1}=\frac{-16-2\sqrt{39}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+2\sqrt{39}}{2*1}=\frac{-16+2\sqrt{39}}{2}
$