# Which polynomial is a difference of two squares? x^{2} + 25 and x^{2} - 25

We will use the algebraic identity a^{2}- b^{2} = (a+b)(a-b) which is also known as the difference of two squares.

## Answer: The polynomial that is the difference of two squares is x^{2} - 25.

Let us see how we will use the concept of factoring polynomials that are used to express the differences between two perfect squares.

**Explanation**:

Given: The polynomials x^{2} + 25 and x^{2} - 25

The difference of two squares or a^{2}- b^{2} formula is a formula that helps us express a quadratic polynomial as a product of two binomials where one shows the sum and the other shows the difference of the two perfect squares respectively.

The formula is a^{2}-b^{2} = (a+b)(a-b)

x^{2} - 25 can be rewritten as x^{2} - 5^{2 }

On multiplying (x+5)(x-5), we get x^{2 }+ 5x - 5x-25 = x^{2} - 25.