Factor the expression. 3x3 + 3x2 + x + 1

3x³ + 3x² + x + 1

Divide into two groups:

[3x³ + 3x²] + [x + 1]             Factor 3x²  out of the first group.

3x²(x + 1) + (x + 1)               Rewrite the second term.

3x²(x + 1) + 1(x + 1)             Factor out the common term of  x + 1.

(x + 1)(3x² + 1)

my bad i meant  3x^3 + 3x^2 + x + 1