### what is the difference of two square formula and how to use it?

The difference of two square formula is: a^{2} - b^{2} = (a + b) (a - b). Using the difference of two square formula, we can factor the polynomial
which has a difference of two square. For example, x^{4} - 16 = (x^{2} + 4)(x^{2} - 4) = (x^{2} + 4)(x + 2)(x - 2). Factoring polynomial
can reduce the degree of a fraction equation. The difference of two square formula is very frequentlly used. The difference of two square is equal to the product of the first number adding the second number
and the first number subtracting the second number.