Area of the garden and the walkway around it: 648 ft²
Dimensions of the garden: 12 ft wide, 15 ft long
From these dimensions, we can draw the garden and the walkway around it (x is the width of the walkway):
Now, we can calculate the width of the walkway using the equation:
Total_area = (2x + 15)*(2x + 12) => This is just the area of the rectangle)
Where x is the width of the walkway
Replacing the area of the walkway, and solving for x:
648 = 4x² + 54x + 180
4x² + 54x - 468 = 0
=> x = 6 ft
Then, the width of the walkway around the garden is 6 feet.
