To solve this problem you must apply the proccedure shown below:
1. You have that:
- The garden measures 6 feet by 7 feet.
- The gravel path has a constant width and it is placed around the garden.
- The total area is 72 square feet.
2. Therefore, let's call:
x: the widht of the gravel path
L1:The lenght of the garden (L1=7 ft).
W1: The widht of the garden (W1=6 ft).
L2=The lenght of the garden + The widht of the gravel path on both sides (L2=L1+2x=7+2X).
W2=The widht of the garden + The widht of the gravel path on both sides (W2=W1+2X=6+2x).
A: The total area (A=72 ft^2).
2. The formula for calculate the area of a rectangle is:
A=LenghxWidth
A=L2xW2
72=(7+2x)(6+2x)
4x^2+26x-30=0
x=1 ft
The answer is: 1 ft.