.5x^2=200

Solution for .5x^2=200 equation:

.5x^2=200

We move all terms to the left:

.5x^2-(200)=0

a = .5; b = 0; c = -200;
Δ = b2-4ac
Δ = 02-4·.5·(-200)
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-20}{2*.5}=\frac{-20}{1}
=-20
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+20}{2*.5}=\frac{20}{1}
=20
$