Answer:
3(3x^3-8)
Step-by-step explanation:
3x^3+6x^3 = 9x^3 (you sure it's not 6x^2??)
if not then 9x^3-24
3(3x^-8)
BUT
if it's 3x^3+6x^2-24
then 3(x^3+2x^2-8)
^-^
