Question 1021309
Perimeter P = 2L + 2W = 100.  We also have
L = 5 + 2W
Now substitute this into the above and get
2(5+2W) + 2W = 100
10 + 4W + 2W = 100
6W + 10 = 100
6W = 90
W = 15 feet
L = 5 + 2(15) = 35 feet
Area A = LW = 525 square feet