X^2+18x=208

Solution for X^2+18x=208 equation:

X^2+18X=208

We move all terms to the left:

X^2+18X-(208)=0

a = 1; b = 18; c = -208;
Δ = b2-4ac
Δ = 182-4·1·(-208)
Δ = 1156
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1156}=34$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-34}{2*1}=\frac{-52}{2}
=-26
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+34}{2*1}=\frac{16}{2}
=8
$