## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$2(x+1)(3x+1)$
We have $6x^2 + 8x + 2=2(3x^2+4x+1)=2(3x^2+3x+x+1)$ By grouping the first two terms and the second two terms, and then taking common factors, we have $$2(3x^2+3x+x+1)=2(3x(x+1)+(x+1))=2(x+1)(3x+1) .$$