# Math Help - Factoring

1. ## Factoring

Factor $4x^3+4x^2-x-1$

2. Originally Posted by william
Factor $4x^3+4x^2-x-1$
Use Grouping 2 and 2.

$4x^3 + 4x^2 - x - 1 = 4x^2(x + 1) - (x + 1) = (x + 1)(4x^2 - 1) = (x + 1)(2x + 1)(2x - 1)$ (the last one is found using DOTS).