In the polynomial below, what number should replace the question mark to produce a difference of squares?

A polynomial is an algebraic equation that consists of more than one term. Otherwise, it is called a monomial. The technique in producing a difference of the squares is completing of the squares method. For a quadratic formula with a general form of ax2 + bx + c = 0, you can determine c such that the formula could be factored into two monomials. The equation would be (b/2) ^2.

For example, if the equation is x^2 + 2x + __ = 0, c is solved as follows:

c = (2/2) ^2 = 1

The equation would be x^2 + 2x + 1 = 0. When you simplify and factor it out, the equation would become (x+1) ^2 = 0.