Which statement is true about the polynomial [tex]5s^6 t^2 + 6st^9 - 8s^6 t^2 - 6t^7[/tex] after it has been fully simplified?

A. It has 3 terms and a degree of 9.
B. It has 3 terms and a degree of 10.
C. It has 4 terms and a degree of 9.
D. It has 4 terms and a degree of 10.



Answer :

Let's analyze and simplify the given polynomial step-by-step:

The given polynomial is:
[tex]\[5 s^6 t^2 + 6 s t^9 - 8 s^6 t^2 - 6 t^7\][/tex]

Step 1: Combine like terms

We notice that there are like terms involving [tex]\(s^6 t^2\)[/tex].

Combine the coefficients of [tex]\(s^6 t^2\)[/tex]:
[tex]\[5 s^6 t^2 - 8 s^6 t^2 = (5 - 8) s^6 t^2 = -3 s^6 t^2\][/tex]

After combining the like terms, the polynomial becomes:
[tex]\[-3 s^6 t^2 + 6 s t^9 - 6 t^7\][/tex]

Step 2: Count the number of terms

The simplified polynomial has:
[tex]\[-3 s^6 t^2\][/tex]
[tex]\[6 s t^9\][/tex]
[tex]\[-6 t^7\][/tex]

Thus, the polynomial has 3 distinct terms.

Step 3: Determine the degree of the polynomial

The degree of a term in a polynomial is the sum of the exponents of the variables within that term.

- For [tex]\(-3 s^6 t^2\)[/tex], the degree is [tex]\(6 + 2 = 8\)[/tex].
- For [tex]\(6 s t^9\)[/tex], the degree is [tex]\(1 + 9 = 10\)[/tex].
- For [tex]\(-6 t^7\)[/tex], the degree is [tex]\(7\)[/tex].

The highest degree among these terms is [tex]\(10\)[/tex].

Conclusion:

- The simplified polynomial has 3 terms.
- The degree of the polynomial is 10.

Therefore, the true statement about the polynomial after it has been fully simplified is:
It has 3 terms and a degree of 10.