How do you factor the expression 4x21?

1 Answer
Dec 19, 2015

Apply the difference of squares formula to find that
4x21=(2x+1)(2x1)

Explanation:

The difference of squares formula states that
a2b2=(a+b)(ab)
(Verify this by expanding the right hand side)

Applying this to the given problem, we have

4x21=(2x)212=(2x+1)(2x1)