X2+18x+4=0

Solution for X2+18x+4=0 equation:

X2+18X+4=0

We add all the numbers together, and all the variables

X^2+18X+4=0

a = 1; b = 18; c = +4;
Δ = b2-4ac
Δ = 182-4·1·4
Δ = 308
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:

$\sqrt{\Delta}=\sqrt{308}=\sqrt{4*77}=\sqrt{4}*\sqrt{77}=2\sqrt{77}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-2\sqrt{77}}{2*1}=\frac{-18-2\sqrt{77}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+2\sqrt{77}}{2*1}=\frac{-18+2\sqrt{77}}{2}
$