Explanation:
Length = x
Width = (x-5)
Perimeter = 2 lengths + 2 widths
50 ft = x + x + (x-5) + (x-5)
50 ft = 4x - 10
60 ft = 4x
15 ft = x
length = x = 15 ft
width = (x-5) = (15 -5) = 10 ft
dimensions = length × width
= 15 ft × 10 ft
if you wanna check,
50 ft = x + x + (x-5) + (x-5)
50 ft = 15 + 15 + (15-5) + (15-5)
50 ft = 30 +(10+10)
50 ft = 30 + 20
50 ft = 50