4y2-800=0

Solution for 4y2-800=0 equation:

4y^2-800=0

a = 4; b = 0; c = -800;
Δ = b2-4ac
Δ = 02-4·4·(-800)
Δ = 12800
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{12800}=\sqrt{6400*2}=\sqrt{6400}*\sqrt{2}=80\sqrt{2}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-80\sqrt{2}}{2*4}=\frac{0-80\sqrt{2}}{8}
=-\frac{80\sqrt{2}}{8}
=-10\sqrt{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+80\sqrt{2}}{2*4}=\frac{0+80\sqrt{2}}{8}
=\frac{80\sqrt{2}}{8}
=10\sqrt{2}
$