College

Multiply the following expressions:

[tex]
\[
\left(4x^2 + 7x\right)\left(5x^2 - 3x\right)
\]
[/tex]

Choose the correct answer:

A. [tex]\(20x^4 + 35x^3 - 21x^2\)[/tex]

B. [tex]\(20x^4 + 23x^3 - 21x^2\)[/tex]

C. [tex]\(20x^4 + 35x^2 - 21x\)[/tex]

D. [tex]\(20x^4 + 23x^2 - 21x\)[/tex]

Answer :

Sure! Let's multiply the polynomials step by step.

We have the expression [tex]\((4x^2 + 7x)(5x^2 - 3x)\)[/tex]. To solve this, we need to apply the distributive property, also known as the FOIL method (First, Outer, Inner, Last).

1. First: Multiply the first terms from each binomial:
[tex]\[
4x^2 \cdot 5x^2 = 20x^4
\][/tex]

2. Outer: Multiply the outer terms:
[tex]\[
4x^2 \cdot (-3x) = -12x^3
\][/tex]

3. Inner: Multiply the inner terms:
[tex]\[
7x \cdot 5x^2 = 35x^3
\][/tex]

4. Last: Multiply the last terms:
[tex]\[
7x \cdot (-3x) = -21x^2
\][/tex]

Now, let's combine the like terms:

- Combine the [tex]\(x^3\)[/tex] terms:
[tex]\[
-12x^3 + 35x^3 = 23x^3
\][/tex]

As a result, the expression simplifies to:
[tex]\[
20x^4 + 23x^3 - 21x^2
\][/tex]

So, the correct answer is B. [tex]\(20x^4 + 23x^3 - 21x^2\)[/tex].