Answer:
12x3+6x2+34x+17
Step-by-step explanation:
(2x+1)(6x2+8+9)
=(2x+1)(6x2+8+9)
=(2x)(6x2)+(2x)(8)+(2x)(9)+(1)(6x2)+(1)(8)+(1)(9)
=12x3+16x+18x+6x2+8+9
=12x3+6x2+34x+17
