Which is true about the completely simplified difference of the polynomials [tex]$6x^6 - x^3y^4 - 5xy^5$[/tex] and [tex]$4x^5y + 2x^3y^4 + 5xy^5$[/tex]?

A. The difference has 3 terms and a degree of 6.
B. The difference has 4 terms and a degree of 6.
C. The difference has 3 terms and a degree of 7.
D. The difference has 4 terms and a degree of 7.



Answer :

To find the simplified difference of the given polynomials [tex]\( 6x^6 - x^3 y^4 - 5xy^5 \)[/tex] and [tex]\( 4x^5 y + 2x^3 y^4 + 5xy^5 \)[/tex], we will follow these steps:

1. Write the polynomials:

[tex]\[ P_1 = 6x^6 - x^3 y^4 - 5xy^5 \][/tex]
[tex]\[ P_2 = 4x^5 y + 2x^3 y^4 + 5xy^5 \][/tex]

2. Calculate the difference between the polynomials:

[tex]\[ P = P_1 - P_2 = (6x^6 - x^3 y^4 - 5xy^5) - (4x^5 y + 2x^3 y^4 + 5xy^5) \][/tex]

3. Distribute and combine like terms:

[tex]\[ P = 6x^6 - x^3 y^4 - 5xy^5 - 4x^5 y - 2x^3 y^4 - 5xy^5 \][/tex]

Combine the terms with the same degree and exponents:

- [tex]\(6x^6\)[/tex]
- Combine the [tex]\(x^3 y^4\)[/tex] terms: [tex]\(-x^3 y^4 - 2x^3 y^4 = -3x^3 y^4\)[/tex]
- Combine the [tex]\(xy^5\)[/tex] terms: [tex]\(-5xy^5 - 5xy^5 = -10xy^5\)[/tex]
- [tex]\(-4x^5 y\)[/tex]

Therefore:

[tex]\[ P = 6x^6 - 4x^5 y - 3x^3 y^4 - 10xy^5 \][/tex]

4. Count the number of terms in the simplified polynomial:

The polynomial [tex]\( P \)[/tex] has four terms:
- [tex]\(6x^6\)[/tex]
- [tex]\(-4x^5 y\)[/tex]
- [tex]\(-3x^3 y^4\)[/tex]
- [tex]\(-10xy^5\)[/tex]

5. Determine the degree of the simplified polynomial:

The degree of a polynomial is the highest degree of its terms. Evaluate the degrees of each term:
- The degree of [tex]\(6x^6\)[/tex] is 6.
- The degree of [tex]\(-4x^5 y\)[/tex] is [tex]\(5 + 1 = 6\)[/tex].
- The degree of [tex]\(-3x^3 y^4\)[/tex] is [tex]\(3 + 4 = 7\)[/tex].
- The degree of [tex]\(-10xy^5\)[/tex] is [tex]\(1 + 5 = 6\)[/tex].

The highest degree among them is 7.

Therefore, the completely simplified difference of the polynomials has 4 terms and a degree of 7. The correct answer is:

- The difference has 4 terms and a degree of 7.