can't get two answers??

Question

An arrow is shot vertically upward at a rate of 250ft/s. Use the projectile formula h=−16t2+v0t to determine at what time(s), in seconds, the arrow is at a height of 500ft

Answer 1

h = -16t^2 + 250t <--- initial velocity v0 = 250 ft/sec

500 = -16t^2 + 250t

16t^2 - 250t + 500 = 0

8t^2 - 125t + 250 = 0

t = (125 + 5*sqrt(305))/16 = 13.27+ seconds

or

t = (125 - 5*Sqrt(305))/16 = 2.355- seconds

Answer 2

500 = -16t² + 250t

0 = -16t² + 250t - 500

0 = 16t² - 250t + 500

Using the Quadratic Formula:

x = (126 ± 5√305) / 16