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:
20
Step-by-step explanation:
I hope this helps answer your question.
Answer:
471 cm^2
Step-by-step explanation:
to find the literal surface area use formula= A^L=2πrh
2(3.14)(3)(25)=
471cm^2