Answer:
Choice B is correct
Step-by-step explanation:
The given radical division can be expressed in the following form;

Using the properties of radical division, the expression can be expressed in the following form;

Simplifying further yields;

Choice B is thus the correct alternative
Answer:
The ball will be 84 feet above the ground 1.125 seconds and 4.5 seconds after launch.
Step-by-step explanation:
Statement is incorrect. Correct form is presented below:
<em>The height </em>
<em> of an ball that is thrown straight upward from an initial position 3 feet off the ground with initial velocity of 90 feet per second is given by equation </em>
<em>, where </em>
<em> is time in seconds. After how many seconds will the ball be 84 feet above the ground. </em>
We equalize the kinematic formula to 84 feet and solve the resulting second-order polynomial by Quadratic Formula to determine the instants associated with such height:

(1)
By Quadratic Formula:

,
The ball will be 84 feet above the ground 1.125 seconds and 4.5 seconds after launch.
Hello,
Please, see the detailed answer in the attached files.
Thanks.
Answer: 
Step-by-step explanation:
Move all terms to one side.

Use the Quadratic Formula.
, 