College

Multiply the polynomials.

[tex]\left(7x^2 + 5x + 7\right)(4x - 6)[/tex]

A. [tex]28x^3 - 62x^2 - 2x - 42[/tex]
B. [tex]28x^3 - 22x^2 - 2x + 42[/tex]
C. [tex]28x^3 - 22x^2 - 58x - 42[/tex]
D. [tex]28x^3 - 22x^2 - 2x - 42[/tex]

Answer :

Sure! Let's multiply the polynomials [tex]\((7x^2 + 5x + 7)\)[/tex] and [tex]\((4x - 6)\)[/tex] step by step:

1. Distribute each term in [tex]\((4x - 6)\)[/tex] to each term in [tex]\((7x^2 + 5x + 7)\)[/tex]:

- Multiply [tex]\(4x\)[/tex] by each term in [tex]\((7x^2 + 5x + 7)\)[/tex]:
- [tex]\(4x \cdot 7x^2 = 28x^3\)[/tex]
- [tex]\(4x \cdot 5x = 20x^2\)[/tex]
- [tex]\(4x \cdot 7 = 28x\)[/tex]

- Multiply [tex]\(-6\)[/tex] by each term in [tex]\((7x^2 + 5x + 7)\)[/tex]:
- [tex]\(-6 \cdot 7x^2 = -42x^2\)[/tex]
- [tex]\(-6 \cdot 5x = -30x\)[/tex]
- [tex]\(-6 \cdot 7 = -42\)[/tex]

2. Combine all these results together:

[tex]\[
28x^3 + 20x^2 + 28x - 42x^2 - 30x - 42
\][/tex]

3. Combine like terms:

- Combine the [tex]\(x^2\)[/tex] terms: [tex]\(20x^2 - 42x^2 = -22x^2\)[/tex]
- Combine the [tex]\(x\)[/tex] terms: [tex]\(28x - 30x = -2x\)[/tex]

4. Write the final polynomial:

[tex]\[
28x^3 - 22x^2 - 2x - 42
\][/tex]

So, the final answer is:

D. [tex]\(28x^3 - 22x^2 - 2x - 42\)[/tex]