A binomial squared is written like

So, we have 
So, we want to complete the square 
We can add and subtract 9 to write

Answer:
whats the problem?
Step-by-step explanation:
Using the perimeter of a rectangle, it is found that she can make a deck of 122 ft wide.
<h3>What is the perimeter of a rectangle?</h3>
The perimeter of a rectangle of length l and width w is given by:

In this problem:
- She has enough wood to build a deck that is 280ft, hence P = 280.
- The length is of 10 feet, hence l = 10.
- Considering that the deck's width will be added to the actual width of 8 feet, we have that w = 8 + w.
Then:






She can make a deck of 122 ft wide.
You can learn more about the perimeter of a rectangle at brainly.com/question/10489198