Completing the square follows the principle of taking

and converting it into

where d is the 'correctional number' as I like to call it - i.e. the number that converts the expanded bracket into the +c, since the expanded bracket will give us

.
In this case, 2/2=1 so we have the first part:

.
Expanding this gives us

. We need c to be 9, so we can just add 8.
Putting this together:

Now we can solve it more easily.
Rearranging:
Answer:
it is D.4
Step-by-step explanation:
each place on the number line goes up by 4
<span>A unit </span>cube<span> is simply a </span>cube<span> measuring one inch, one centimeter, one </span>foot<span>, or whatever unit of measurement you are using, on all sides. ... </span>If<span> you look carefully, you will see that the </span>volume<span> of the</span>rectangular prism<span> is a function of multiplying the </span>length<span> the </span>width<span> the </span>height<span>. ... First find the </span>area<span> of the</span>base<span>. does that help</span>