-8x2+100=0

Solution for -8x2+100=0 equation:

-8x^2+100=0

a = -8; b = 0; c = +100;
Δ = b2-4ac
Δ = 02-4·(-8)·100
Δ = 3200
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:

$\sqrt{\Delta}=\sqrt{3200}=\sqrt{1600*2}=\sqrt{1600}*\sqrt{2}=40\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-40\sqrt{2}}{2*-8}=\frac{0-40\sqrt{2}}{-16}
=-\frac{40\sqrt{2}}{-16}
=-\frac{5\sqrt{2}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+40\sqrt{2}}{2*-8}=\frac{0+40\sqrt{2}}{-16}
=\frac{40\sqrt{2}}{-16}
=\frac{5\sqrt{2}}{-2}
$