Answer:
(3x^2+5)(x+3)
Step-by-step explanation:
The given expression is:
3x3 + 9x2 + 5x + 15
First of all group the first two terms and last two terms:
(3x3 + 9x2) + (5x + 15)
Now factor out the greatest common factor from each group:
3x^2(x+3)+5(x+3)
(3x^2+5)(x+3)
Thus the factors of 3x3 + 9x2 + 5x + 15 are:
(3x^2+5)(x+3) ....
