0=-16x^2-64x+500

Solution for 0=-16x^2-64x+500 equation:

0=-16x^2-64x+500

We move all terms to the left:

0-(-16x^2-64x+500)=0

We add all the numbers together, and all the variables

-(-16x^2-64x+500)=0

We get rid of parentheses

16x^2+64x-500=0

a = 16; b = 64; c = -500;
Δ = b2-4ac
Δ = 642-4·16·(-500)
Δ = 36096
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:

$\sqrt{\Delta}=\sqrt{36096}=\sqrt{256*141}=\sqrt{256}*\sqrt{141}=16\sqrt{141}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(64)-16\sqrt{141}}{2*16}=\frac{-64-16\sqrt{141}}{32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(64)+16\sqrt{141}}{2*16}=\frac{-64+16\sqrt{141}}{32}
$