0=-16x^2+40x+25

Solution for 0=-16x^2+40x+25 equation:

0=-16x^2+40x+25

We move all terms to the left:

0-(-16x^2+40x+25)=0

We add all the numbers together, and all the variables

-(-16x^2+40x+25)=0

We get rid of parentheses

16x^2-40x-25=0

a = 16; b = -40; c = -25;
Δ = b2-4ac
Δ = -402-4·16·(-25)
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{-(-40)-40\sqrt{2}}{2*16}=\frac{40-40\sqrt{2}}{32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+40\sqrt{2}}{2*16}=\frac{40+40\sqrt{2}}{32}
$