How do you factor 4x^2-26?

1 Answer
May 14, 2016

4x^2-26 = (2x-sqrt(26))(2x+sqrt(26))

Explanation:

The difference of squares identity can be written:

a^2-b^2 = (a-b)(a+b)

The first term of our expression is a perfect square:

4x^2 = (2x)^2.

The second term can be written as a square of its square root:

26 = (sqrt(26))^2

Hence we can factor:

4x^2-26 = (2x)^2-(sqrt(26))^2 = (2x-sqrt(26))(2x+sqrt(26))