The area of a square is [tex]A = s^{2} [/tex], where s = length of a side of the square. You know the length of the square shaped traffic sign's side is s = 2x-1. Plug that value into the equation for the area of the square and foil:
[tex]A = s^{2} \\
A = (2x-1)^{2} \\
A = (2x-1)(2x-1)\\
A = 4x^{2} - 4x + 1[/tex]
The area of the square sign is D) [tex] 4x^{2} - 4x + 1[/tex]