Answer:
[tex] {3x}^{4} + {8x}^{3} + {6x}^{2} [/tex]
Step-by-step explanation:
[tex] {3x}^{3} (x + 2) + 2x( {x}^{2} + 3x)[/tex]
[tex] {3x}^{4} + {6x}^{3} + {2x}^{3} + {6x}^{2} [/tex]