College

Multiply:

[tex]\left(x^4+1\right)\left(3x^2+9x+2\right)[/tex]

A. [tex]x^4+3x^2+9x+3[/tex]

B. [tex]3x^6+9x^5+2x^4+3x^2+9x+2[/tex]

C. [tex]3x^7+9x^6+2x^5[/tex]

D. [tex]3x^8+9x^4+2x^4+3x^2+9x+2[/tex]

Answer :

Sure, let's multiply the polynomials step by step:

Given:
[tex]\[
(x^4 + 1)(3x^2 + 9x + 2)
\][/tex]

We will use the distributive property to multiply these polynomials. Let's distribute each term in the first polynomial across every term in the second polynomial.

### Step-by-Step Multiplication

1. Multiply [tex]\(x^4\)[/tex] by each term in [tex]\(3x^2 + 9x + 2\)[/tex]:
[tex]\[
x^4 \cdot 3x^2 = 3x^6
\][/tex]
[tex]\[
x^4 \cdot 9x = 9x^5
\][/tex]
[tex]\[
x^4 \cdot 2 = 2x^4
\][/tex]

2. Multiply [tex]\(1\)[/tex] by each term in [tex]\(3x^2 + 9x + 2\)[/tex]:
[tex]\[
1 \cdot 3x^2 = 3x^2
\][/tex]
[tex]\[
1 \cdot 9x = 9x
\][/tex]
[tex]\[
1 \cdot 2 = 2
\][/tex]

Now, we add all these results together:
[tex]\[
3x^6 + 9x^5 + 2x^4 + 3x^2 + 9x + 2
\][/tex]

### Final Answer

The product of the polynomials [tex]\((x^4 + 1)\)[/tex] and [tex]\((3x^2 + 9x + 2)\)[/tex] is:
[tex]\[
3x^6 + 9x^5 + 2x^4 + 3x^2 + 9x + 2
\][/tex]