Factor the expression.

3x3 + 3x2 + x + 1

(x + 3) (3x2 - 1)

(x + 1) (3x2 + 1)

3x2 (x + 1)

x (3x2 + x + 1)

(x + 1) (3 x^2 + 1)

Step-by-step explanation:

Factor the following:

3 x^3 + 3 x^2 + x + 1

Factor terms by grouping. 3 x^3 + 3 x^2 + x + 1 = (3 x^3 + 3 x^2) + (x + 1) = 3 x^2 (x + 1) + (x + 1):

3 x^2 (x + 1) + (x + 1)

Factor x + 1 from 3 x^2 (x + 1) + (x + 1):

Answer: (x + 1) (3 x^2 + 1)