Answer:

Step-by-step explanation:
We have been given that the area of a square is given by
, where x is the length of one side.
Mary's original garden was in the shape of a square. She has decided to double the area of her garden. So the new area of Mary's garden will be 2 times the area of original garden.
We can represent this information in an equation as:

Therefore, the expression
will represent the area of Mary's new garden.
To evaluate the area of new garden, if the side length of Mary's original garden was 8 feet, we will substitute x equals 8 in our expression.



Therefore, the area of Mary's new garden will be 128 square feet.