Answer:
Total Cost to tile = $273.28
Let x be the Width; then
3x - 9 = Length; hence
2(W + L) = Perimeter; therefore
6x = 2(x + 3x - 9)
6x = 2(4x - 9) = 8x - 18
6x - 8x = -18
-2x = -18
x = 9
Width = x = 9 ft
Length = 3x - 9 = 3 times 9, minus 9 = 27 - 9 = 18 ft
Area = W times L = 9 ft. times 18 ft. = 162 sq. ft.
Cost of Tile = $1.69 per sq. ft.
Total Cost = $1.69 times 162 = $273.28
To check:
Perimeter = 6(W) = 6x = 6 times 9 ft. = 54 ft.; also
Perimeter = 2(W + L) = 2(9 + 18) = 2(27) = 54 ft