Help on one quadratic equation problem

I tried it myself but i have a feeling I got it wrong :( Here is the formula:
y= -16x^2 + vx + s (plug in 250 for v) (plug in 0 for s)
The find a,b,c values
Plug those values into the quadratric formula and please tell me what you got after you simplified, I think I messed up,. Thanks!! (:

In the end after using the, i got approx. 0 and approx. 15.65

y= -16x^2 + vx + s (plug in 250 for v) (plug in 0 for s)

y = -16x^2 + 250x

y = x(250 - 16x)

if you are looking for solutions for y=0 then

x=0 and 16x = 250 so x = 250/16 = 15.625

- 16*x^2 + 250*x = 0

- x*(16*x - 250) = 0

x1 = 0
x2 = 250/16 = 15.625

If you want to apply the quadratic formula:

a = - 16, b = 250, c = 0

b^2 - 4*a*c = 250^2 - 4*( - 16)*0 = 250^2

x1 = ( - 250 + 250)/( - 32) = 0

x2 = ( - 250 - 250)/( - 32) = 500/32 = 15.625

i got x=15.625 and 0