Find the difference of the polynomials given below and classify it in terms of degree and number of terms.

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

A. [tex]4^{\text{th}}[/tex] degree polynomial with 5 terms
B. [tex]4^{\text{th}}[/tex] degree polynomial with 4 terms
C. [tex]3^{\text{rd}}[/tex] degree polynomial with 4 terms
D. [tex]3^{\text{rd}}[/tex] degree polynomial with 5 terms



Answer :

To tackle this problem, let's break it down step-by-step.

1. Expand the polynomials:
Start by expanding the given polynomials to make the calculation of their difference easier.

The first polynomial is:
[tex]\[ 3n^2(n^2 + 4n - 5) \][/tex]

Let's expand it:
[tex]\[ 3n^2 \cdot n^2 + 3n^2 \cdot 4n - 3n^2 \cdot 5 \][/tex]
[tex]\[ = 3n^4 + 12n^3 - 15n^2 \][/tex]

The second polynomial is:
[tex]\[ 2n^2 - n^4 + 3 \][/tex]

2. Write the expression for the difference of the polynomials:
Now, to find the difference, subtract the second polynomial from the first polynomial:
[tex]\[ (3n^4 + 12n^3 - 15n^2) - (2n^2 - n^4 + 3) \][/tex]

3. Distribute the negative sign and combine like terms:
Distribute the negative sign through the second polynomial:
[tex]\[ 3n^4 + 12n^3 - 15n^2 - 2n^2 + n^4 - 3 \][/tex]

Now, combine the like terms:
[tex]\[ 3n^4 + n^4 + 12n^3 - 15n^2 - 2n^2 - 3 \][/tex]

Combine the terms with the same degree:
[tex]\[ (3n^4 + n^4) + 12n^3 + (-15n^2 - 2n^2) - 3 \][/tex]
[tex]\[ = 4n^4 + 12n^3 - 17n^2 - 3 \][/tex]

4. Classify the resulting polynomial:
Now that we have the resulting polynomial in its simplified form:
[tex]\[ 4n^4 + 12n^3 - 17n^2 - 3 \][/tex]

- The leading term is [tex]\(4n^4\)[/tex], so the degree of the polynomial is 4.
- The polynomial has four terms: [tex]\(4n^4\)[/tex], [tex]\(12n^3\)[/tex], [tex]\(-17n^2\)[/tex], and [tex]\(-3\)[/tex].

Hence, we have a [tex]\(4^{\text{th}}\)[/tex] degree polynomial with 4 terms. Therefore, the correct answer is:

B. [tex]\(4^{\text{th}}\)[/tex] degree polynomial with 4 terms