X^2+4.y=8

Solution for X^2+4.y=8 equation:

X^2+4.X=8

We move all terms to the left:

X^2+4.X-(8)=0

a = 1; b = 4.; c = -8;
Δ = b2-4ac
Δ = 4.2-4·1·(-8)
Δ = 48
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:

$\sqrt{\Delta}=\sqrt{48}=\sqrt{16*3}=\sqrt{16}*\sqrt{3}=4\sqrt{3}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4.)-4\sqrt{3}}{2*1}=\frac{-4-4\sqrt{3}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4.)+4\sqrt{3}}{2*1}=\frac{-4+4\sqrt{3}}{2}
$