We have been given that Ben has a square garden that has sides measuring X feet, Ben wants to increase every side of his garden by 11 feet in order to plant more vegetables. So each side of garden would be
.
We are also told that after Ben increased his garden it will have a perimeter of 104 feet.
We know that perimeter of square is 4 times the side length. So perimeter of garden after enlargement would be
.
Now we will equate perimeter of new garden with 104 as:

Therefore, the equation
can be used to solve for X.




Therefore, the value of X is 15 feet.