Given:
Dimensions of lot is (7+x) and (7-x).
Dimension of house is (3+x) and (3-x)
Taylor is thinking about extending the house by adding 3 feet to the length and width.
So, the dimension of house becomes (6+x) feet and (6-x) feet.
Now, the area of the yard is,

Answer: area for the yard left is 13 square feet.