College

What is the product of the polynomials below?

[tex]\left(5x^2-x-3\right)(2x+6)[/tex]

A. [tex]10x^3+28x^2-12x-3[/tex]

B. [tex]10x^3+28x^2+12x+3[/tex]

C. [tex]10x^3+28x^2-12x-18[/tex]

D. [tex]10x^3+28x^2+12x+18[/tex]

Answer :

To find the product of the polynomials [tex]\((5x^2 - x - 3)(2x + 6)\)[/tex], you can use the distributive property to multiply each term from the first polynomial by each term in the second polynomial. Here's how it works step-by-step:

1. Distribute [tex]\(5x^2\)[/tex]:
- Multiply [tex]\(5x^2\)[/tex] by [tex]\(2x\)[/tex]: [tex]\(5x^2 \times 2x = 10x^3\)[/tex]
- Multiply [tex]\(5x^2\)[/tex] by [tex]\(6\)[/tex]: [tex]\(5x^2 \times 6 = 30x^2\)[/tex]

2. Distribute [tex]\(-x\)[/tex]:
- Multiply [tex]\(-x\)[/tex] by [tex]\(2x\)[/tex]: [tex]\(-x \times 2x = -2x^2\)[/tex]
- Multiply [tex]\(-x\)[/tex] by [tex]\(6\)[/tex]: [tex]\(-x \times 6 = -6x\)[/tex]

3. Distribute [tex]\(-3\)[/tex]:
- Multiply [tex]\(-3\)[/tex] by [tex]\(2x\)[/tex]: [tex]\(-3 \times 2x = -6x\)[/tex]
- Multiply [tex]\(-3\)[/tex] by [tex]\(6\)[/tex]: [tex]\(-3 \times 6 = -18\)[/tex]

4. Combine all the products:
- After distributing, collect the terms:
[tex]\(10x^3 + 30x^2 - 2x^2 - 6x - 6x - 18\)[/tex]

5. Combine like terms:
- Combine the [tex]\(x^2\)[/tex] terms: [tex]\(30x^2 - 2x^2 = 28x^2\)[/tex]
- Combine the [tex]\(x\)[/tex] terms: [tex]\(-6x - 6x = -12x\)[/tex]

Putting it all together gives us the final product:

[tex]\[10x^3 + 28x^2 - 12x - 18\][/tex]

Therefore, the correct answer is:

C. [tex]\(10x^3 + 28x^2 - 12x - 18\)[/tex]