If - 1 is a zero then

is a factor.
Dividing with this factor using the long division approach, we get the quadratic factor to be,

(see attachment).
We can rewrite the polynomial as

We can further factor as

That is
Given:
t = 1/2 √v
v = speed of object meters per second
t = 3 seconds
3 = 1/2 √v
3 * 2 = √v
6 = √v
6² = √v²
36 meters = v
v = 36 meters per second
45 i believe it is i may be wrong!!!