I got this, I hope it solves your question
Yes I got the third one too
What? Can you be more specific? I'm very confused about what you want
Answer: Option D

Step-by-step explanation:
Note that the projectile height as a function of time is given by the quadratic equation

To find the maximum height of the projectile we must find the maximum value of the quadratic function.
By definition the maximum value of a quadratic equation of the form
is located on the vertex of the parabola:

Where 
In this case the equation is: 
Then

So:


Answer:

Step-by-step explanation:
can be represented as
and
can be represented as
. Therefore, the expression can be rewritten as:

The rule for multiplying two exponents with the same base is you add the exponents. For example: 
We can use the same property to get:

which is just
after you add the fractions