Which is true about the completely simplified difference of the polynomials [tex]\( a^3 b + 9a^2 b^2 - 4ab^5 \)[/tex] and [tex]\( a^3 b - 3a^2 b^2 + ab^5 \)[/tex]?

A. The difference is a binomial with a degree of 5.
B. The difference is a binomial with a degree of 6.
C. The difference is a trinomial with a degree of 5.
D. The difference is a trinomial with a degree of 6.



Answer :

To determine the true statement about the completely simplified difference of the given polynomials [tex]\( a^3 b + 9 a^2 b^2 - 4 a b^5 \)[/tex] and [tex]\( a^3 b - 3 a^2 b^2 + a b^5 \)[/tex], let's follow these steps:

1. Write down the given polynomials:
- [tex]\( \text{poly1} = a^3 b + 9 a^2 b^2 - 4 a b^5 \)[/tex]
- [tex]\( \text{poly2} = a^3 b - 3 a^2 b^2 + a b^5 \)[/tex]

2. Calculate the difference of the polynomials:
[tex]\( \text{difference} = \text{poly1} - \text{poly2} \)[/tex]

Subtract each term of [tex]\(\text{poly2}\)[/tex] from the corresponding term in [tex]\(\text{poly1}\)[/tex]:
[tex]\[ \text{difference} = (a^3 b + 9 a^2 b^2 - 4 a b^5) - (a^3 b - 3 a^2 b^2 + a b^5) \][/tex]

3. Combine like terms:
[tex]\[ \text{difference} = (a^3 b - a^3 b) + (9 a^2 b^2 + 3 a^2 b^2) - (4 a b^5 + a b^5) \][/tex]
Simplifying each group:
[tex]\[ \text{difference} = 0 + 12 a^2 b^2 - 5 a b^5 \][/tex]

4. Simplify the expression:
[tex]\[ \text{difference} = 12 a^2 b^2 - 5 a b^5 \][/tex]

The simplified difference is [tex]\( 12 a^2 b^2 - 5 a b^5 \)[/tex].

5. Determine the number of terms and the degree:
- There are 2 terms in the simplified difference.
- The degree is the highest sum of the exponents in any term. The term [tex]\( -5 a b^5 \)[/tex] has a degree of [tex]\( 1 + 5 = 6 \)[/tex] and the term [tex]\( 12 a^2 b^2 \)[/tex] has a degree of [tex]\( 2 + 2 = 4 \)[/tex]. Therefore, the overall degree is the highest of these, which is 6.

6. Conclusion:
The correct statement about the completely simplified difference of the polynomials is:
- The difference is a binomial (because it has two terms) with a degree of 6.

Therefore, the correct answer is:

The difference is a binomial with a degree of 6.