x^2-117=-4x

Solution for x^2-117=-4x equation:

x^2-117=-4x

We move all terms to the left:

x^2-117-(-4x)=0

We get rid of parentheses

x^2+4x-117=0

a = 1; b = 4; c = -117;
Δ = b2-4ac
Δ = 42-4·1·(-117)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-22}{2*1}=\frac{-26}{2}
=-13
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+22}{2*1}=\frac{18}{2}
=9
$