What is the product of the polynomials below?

[tex]\[
\left(3x^2 - 2x - 3\right)\left(5x^2 + 4x + 5\right)
\][/tex]

A. [tex]\(15x^4 + 2x^3 - 8x^2 - 22x - 15\)[/tex]

B. [tex]\(15x^4 + 2x^3 - 8x^2 - 22x + 26\)[/tex]

C. [tex]\(15x^4 + 2x^3 - 8x^2 - 2x + 2\)[/tex]

D. [tex]\(15x^4 + 2x^3 - 8x^2 - 2x - 15\)[/tex]



Answer :

To find the product of the polynomials [tex]\((3x^2 - 2x - 3)\)[/tex] and [tex]\((5x^2 + 4x + 5)\)[/tex], we need to apply the distributive property (also known as the FOIL method for binomials, extended here for trinomials).

We first write the product in an expanded form:

[tex]\[ (3x^2 - 2x - 3)(5x^2 + 4x + 5) \][/tex]

Next, we distribute each term from the first polynomial to each term in the second polynomial:

[tex]\[ 3x^2(5x^2 + 4x + 5) - 2x(5x^2 + 4x + 5) - 3(5x^2 + 4x + 5) \][/tex]

Now, we compute the product term-by-term:

[tex]\[ 3x^2 \cdot 5x^2 = 15x^4 \][/tex]
[tex]\[ 3x^2 \cdot 4x = 12x^3 \][/tex]
[tex]\[ 3x^2 \cdot 5 = 15x^2 \][/tex]

[tex]\[ -2x \cdot 5x^2 = -10x^3 \][/tex]
[tex]\[ -2x \cdot 4x = -8x^2 \][/tex]
[tex]\[ -2x \cdot 5 = -10x \][/tex]

[tex]\[ -3 \cdot 5x^2 = -15x^2 \][/tex]
[tex]\[ -3 \cdot 4x = -12x \][/tex]
[tex]\[ -3 \cdot 5 = -15 \][/tex]

Now, we combine all these terms together:

[tex]\[ 15x^4 + 12x^3 + 15x^2 - 10x^3 - 8x^2 - 10x - 15x^2 - 12x - 15 \][/tex]

Next, we combine like terms:

[tex]\[ 15x^4 + (12x^3 - 10x^3) + (15x^2 - 8x^2 - 15x^2) + (-10x - 12x) - 15 \][/tex]

Simplifying further, we get:

[tex]\[ 15x^4 + 2x^3 - 8x^2 - 22x - 15 \][/tex]

Thus, the product of the polynomials [tex]\((3x^2 - 2x - 3)\)[/tex] and [tex]\((5x^2 + 4x + 5)\)[/tex] is:

[tex]\[ 15x^4 + 2x^3 - 8x^2 - 22x - 15 \][/tex]

So, the correct option is:

A. [tex]\(15x^4 + 2x^3 - 8x^2 - 22x - 15\)[/tex]