Answer: A = (7ft + x)*(6ft + x)
Step-by-step explanation:
The area of a rectangle is equal to A = L*W
where W is width and L is lenght.
Here we have that the width is 6 feet + x feet and the lenght is 7 feet + x feet
(because we also are counting the area of the sidewalk)
Then the total area is:
A = (7ft + x)*(6ft + x)