John wants to fence in a portion of his backyard. how many feet of fencing does john need to buy to enclose this area? how many square yards of carpet will she need to complete the room?

For this problem you need to find the area.
To find area, you multiply the width by the length.
You multiply 12 1/2 by 5 1/2 and you get 31 1/4
This is how you do it::

= 25/2 × 5/2

= (25 × 5) / (2 × 2)

= 125/4

= 125/4

= 31 1/4

So you know that the area is 31 1/4 yards. 
In the question it asks HOW MANY FEET so we have to convert 31 1/4 yards to feet. 
1 yard= 3 feet
31 1/4 *3= 93.75
John need to buy 93.75 feet of fencing to enclose the area.