(x+8)(x+8)=324

Solution for (x+8)(x+8)=324 equation:

(x+8)(x+8)=324

We move all terms to the left:

(x+8)(x+8)-(324)=0

We multiply parentheses ..

(+x^2+8x+8x+64)-324=0

We get rid of parentheses

x^2+8x+8x+64-324=0

We add all the numbers together, and all the variables

x^2+16x-260=0

a = 1; b = 16; c = -260;
Δ = b2-4ac
Δ = 162-4·1·(-260)
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-36}{2*1}=\frac{-52}{2}
=-26
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+36}{2*1}=\frac{20}{2}
=10
$