Final answer:
The cost to replace the window is $343.
Step-by-step explanation:
To find the cost of replacing the window, we need to find the area of the window and multiply it by the cost per square foot of glass.
The window is in the shape of a square with side lengths of 7 feet. The area of a square is found by multiplying the length of one side by itself, so the area of the window is 7 feet * 7 feet = 49 square feet.
Since the glass costs $7 for each square foot, we can multiply the area of the window by the cost per square foot to find the total cost. 49 square feet * $7/square foot = $343.