College

Use polynomial identities to multiply [tex]\left(5-4x^3\right)\left(5+4x^3\right)[/tex].

A. [tex]25-4x^9[/tex]
B. [tex]25-40x^3+16x^6[/tex]
C. [tex]25-4x^6[/tex]
D. [tex]25-16x^6[/tex]

Answer :

Let's use polynomial identities to multiply [tex]\(\left(5-4x^3\right)\left(5+4x^3\right)\)[/tex].

This expression is of the form [tex]\((a - b)(a + b)\)[/tex], which is a difference of squares identity. The difference of squares identity states that:

[tex]\[
(a - b)(a + b) = a^2 - b^2
\][/tex]

Here, we have:
- [tex]\(a = 5\)[/tex]
- [tex]\(b = 4x^3\)[/tex]

Using the difference of squares identity, we get:

[tex]\[
(a - b)(a + b) = a^2 - b^2
\][/tex]

Plugging in [tex]\(a\)[/tex] and [tex]\(b\)[/tex]:

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

Now, calculate each term separately:

[tex]\[
5^2 = 25
\][/tex]
[tex]\[
(4x^3)^2 = 4^2 \cdot (x^3)^2 = 16x^6
\][/tex]

So, the expression simplifies to:

[tex]\[
25 - 16x^6
\][/tex]

Therefore, the result of multiplying [tex]\(\left(5-4x^3\right)\left(5+4x^3\right)\)[/tex] is:

[tex]\[
\boxed{25 - 16x^6}
\][/tex]

So, the correct answer is:

D. [tex]\(25 - 16 x^6\)[/tex]