Seems like you already have the answer so peace
The equation represents height as a function of time.
The bullet was in the air for 75 seconds.
The equation is given as:

The time spent in the air is the time it takes the bullet to land on the ground.
When the bullet is on the ground, the height is:

So, we have:


Factor out t

Split
or 
represents when the shot is fired.
So, we solve for t in 
Collect like terms

Divide both sides by 16

Hence, the bullet was in the air for 75 seconds
Read more about height and time at:
brainly.com/question/2261757
Two column proofs are organized into statement and reason columns. Each statement must be justified in the reason column. The
reason column will typically include "given", vocabulary definitions, and theorems.
Therefore, w<span>hat can be used as a reason in a two-column proof are:
Postulates
Definitions</span>
I^22 = i^(20 + 2) = i^20 x i^2 = (i^4)^(5) x (i)^2 = 1 x -1 = -1