Answer:
Answer C:[tex]3x(2+3x^{2})[/tex]
Answer D:[tex]4x^{2}(3x-1)[/tex]
Step-by-step explanation:
Question C: [tex]6x+9x^{3}=6x+3x*3x=3x(2+3x^{2})[/tex]
Question D: [tex]12x^{3}-4x^{2}=4x^{2}(3x-1)[/tex]
