Respuesta :

Answer:

(x+3)( 3x^2 +5)

Step-by-step explanation:

3x^3+9x^2+5x+15​

Split into two groups

3x^3+9x^2     +5x+15​

Factor 3x^2 out of the  first group and 5 out of the second group

3x^2 ( x+3)  + 5(x+3)

Factor out x+3

(x+3)( 3x^2 +5)

Answer:

^^^^^

(3x^2+5)(x+3)

Step-by-step explanation: