Answer:
[tex]D)\:(3x^{2} +2)(x+4)[/tex]
Step-by-step explanation:
[tex]3x^{3} + 12x^{2} + 2x + 8[/tex]
Group, [tex]3x^3+12x^2+2x+8[/tex] [tex]=(3x^{3} +12x^{2} )+(2x+8)[/tex]factor out [tex]3x^{2}[/tex]in the first and 2 in the second group.
[tex]3x^{2} (x+4)+2(x+4)[/tex]
Factor out common term [tex]x+4[/tex] by using distributive property.
polynomial [tex]3x^{2} +2[/tex] is not factored since it does not have any rational roots.
[tex](3x^{2} +2)(x+4)[/tex]
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