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



Answer :

To solve the problem of finding the difference between the two given polynomials and classifying the resulting polynomial in terms of its degree and number of terms, let's proceed step-by-step:

1. Expand and Simplify the Given Polynomials:

The first polynomial is:
[tex]\[ 3n^2 \left(n^2 + 4n - 5\right) \][/tex]
Let's expand this polynomial.
[tex]\[ 3n^2 \cdot n^2 + 3n^2 \cdot 4n - 3n^2 \cdot 5 = 3n^4 + 12n^3 - 15n^2 \][/tex]

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

2. Subtract the Second Polynomial from the First Polynomial:

[tex]\[ \left(3n^4 + 12n^3 - 15n^2\right) - \left(2n^2 - n^4 + 3\right) \][/tex]

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

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

This results in:
[tex]\[ 4n^4 + 12n^3 - 17n^2 - 3 \][/tex]

3. Determine the Degree of the Resulting Polynomial:

The degree of a polynomial is the highest power of the variable [tex]\(n\)[/tex] in it. In this case, the highest exponent of [tex]\(n\)[/tex] is 4.

4. Count the Number of Terms in the Resulting Polynomial:

The resulting polynomial [tex]\(4n^4 + 12n^3 - 17n^2 - 3\)[/tex] has 4 distinct terms:
[tex]\[ 4n^4, \ 12n^3, \ -17n^2, \text{ and } -3 \][/tex]

5. Classify the Polynomial:

The polynomial we obtained is a 4th-degree polynomial with 4 terms.

Therefore, the correct classification of the polynomial difference is:
[tex]\[ \boxed{\text{C. 4th degree polynomial with 4 terms}} \][/tex]