17\20 should be the correct answer
5.3851648071..... is the irrational number your looking for
Answer:
16 seconds (Approximately)
Step-by-step explanation:
Given:
The function that gives the distance of snowboarder from the bottom of hill with time 'x' is:

Final position of the snowboarder is 
Now, plugging in 100 for 'd' and solving for 'x', we get:

Adding -1100 both sides, we get:

Dividing both sides by -4, we get:

Taking square root and neglecting the negative root as time can't be negative. So,

Therefore, after 16 seconds, the snowboarder will be at a distance of 100 ft from bottom of hill.
The expansion of a perfect square is

In words, the square of a sum of two terms is the sum of the squares of the two terms (
and
), plus twice the product of the two terms (
)
So, when determining if you have a perfect square trinomial, you should have two perfect squares. Note that they don't have to be the first and third term, since you can rearrange terms as you prefer.