(x*x)+(x*8)=308

Solution for (x*x)+(x*8)=308 equation:

(x*x)+(x*8)=308

We move all terms to the left:

(x*x)+(x*8)-(308)=0

We add all the numbers together, and all the variables

(+x*x)+(+x*8)-308=0

We get rid of parentheses

x*x+x*8-308=0

Wy multiply elements

x^2+8x-308=0

a = 1; b = 8; c = -308;
Δ = b2-4ac
Δ = 82-4·1·(-308)
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{-(8)-36}{2*1}=\frac{-44}{2}
=-22
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+36}{2*1}=\frac{28}{2}
=14
$