X^2+18x=211

Solution for X^2+18x=211 equation:

X^2+18X=211

We move all terms to the left:

X^2+18X-(211)=0

a = 1; b = 18; c = -211;
Δ = b2-4ac
Δ = 182-4·1·(-211)
Δ = 1168
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:

$\sqrt{\Delta}=\sqrt{1168}=\sqrt{16*73}=\sqrt{16}*\sqrt{73}=4\sqrt{73}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-4\sqrt{73}}{2*1}=\frac{-18-4\sqrt{73}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+4\sqrt{73}}{2*1}=\frac{-18+4\sqrt{73}}{2}
$