High School

What is the difference of the polynomials?

[tex]\left(5x^3 + 4x^2\right) - \left(6x^2 - 2x - 9\right)[/tex]

A. [tex]-x^3 + 6x^2 + 9[/tex]

B. [tex]-x^3 + 2x^2 - 9[/tex]

C. [tex]5x^3 - 2x^2 - 2x - 9[/tex]

D. [tex]5x^3 - 2x^2 + 2x + 9[/tex]

Answer :

We want to find the difference between the two polynomials:

[tex]$$ (5x^3 + 4x^2) - (6x^2 - 2x - 9). $$[/tex]

Step 1. Distribute the Negative Sign

Distribute the minus sign through the second polynomial:

[tex]\[
(5x^3 + 4x^2) - (6x^2 - 2x - 9) = 5x^3 + 4x^2 - 6x^2 + 2x + 9.
\][/tex]

Step 2. Combine Like Terms

Now, group and combine the like terms:

- The cubic term: [tex]\(\;5x^3\)[/tex].
- The quadratic terms: [tex]\(\;4x^2 - 6x^2 = -2x^2\)[/tex].
- The linear term: [tex]\(\;2x\)[/tex].
- The constant term: [tex]\(\;9\)[/tex].

Thus, the expression simplifies to:

[tex]\[
5x^3 - 2x^2 + 2x + 9.
\][/tex]

Final Answer

The difference of the polynomials is:

[tex]$$ \boxed{5x^3 - 2x^2 + 2x + 9}. $$[/tex]