A square is 12 inches on each side. A small square, x inches on each side, is cut out from each corner of the original square. Represent the area of the remaining portion of the square in the form of a polynomial function A (x).

If x is cut off from each side of the square, this means that the dimension of the new square is equal to 12-2x. Then, we know that the area of the square is determined by squaring its side such that,

A = (12 - 2x) ²

Simplifying the equation,

A (x) = 144 - 48x - 4x²