200=8x2

Solution for 200=8x2 equation:

200=8x^2

We move all terms to the left:

200-(8x^2)=0

a = -8; b = 0; c = +200;
Δ = b2-4ac
Δ = 02-4·(-8)·200
Δ = 6400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6400}=80$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-80}{2*-8}=\frac{-80}{-16}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+80}{2*-8}=\frac{80}{-16}
=-5
$