-16x^2+200x+6.25=0

Solution for -16x^2+200x+6.25=0 equation:

-16x^2+200x+6.25=0

a = -16; b = 200; c = +6.25;
Δ = b2-4ac
Δ = 2002-4·(-16)·6.25
Δ = 40400
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:

$\sqrt{\Delta}=\sqrt{40400}=\sqrt{400*101}=\sqrt{400}*\sqrt{101}=20\sqrt{101}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(200)-20\sqrt{101}}{2*-16}=\frac{-200-20\sqrt{101}}{-32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(200)+20\sqrt{101}}{2*-16}=\frac{-200+20\sqrt{101}}{-32}
$