How do you factor completely 3x^3+9x^2+x+3?

1 Answer
Dec 16, 2016

3x^3+9x^2+x+3 = (3x^2+1)(x + 3)

Explanation:

This factors by grouping, as:
3x^3+9x^2+x+3 = 3x^2*x + 3x^2*3+x+3
" " = 3x^2(x + 3)+(x+3)
" " = (3x^2+1)(x + 3)

The quadratic term does not factorise further, so this is the fully factorised form.