As your question is stated, there is no answer!
I'm going to assume the polynomial you meant is:

To create a perfect square trinomial, take half the coefficient of x and then square it.

In all problems like this, you want to square half the coefficient of x -- always half.
Yes. It is a yes Bc a yes is a yes and another yes
For the first Listing Exercise:
(NOT A)
1. 5x + 65 = 5(x + 13) because if you apply distributive property to the one from List B, it would equal the same as List A's answer.
2. 5(x + 1) = 5x + 5 because if you apply distributive property to the equation from List A, it would equal the same as the one from List B.
3. 1 + 5x = 5x + 1 because this is simple commutative property.. switching the placements.
FORMULA: AREA = LENGTH X WIDTH
with this we can proceed so the area is 20
the length is 40 inches and
answer is : width ----18.94---