High School

Add the following expressions:

[tex]\left(8x^8 - 9x^3 + 3x^2 + 9\right) + \left(4x^7 + 6x^3 - 2x\right)[/tex]

A. [tex]8x^8 + 4x^7 + 3x^3 + 3x^2 - 2x + 9[/tex]

B. [tex]12x^8 - 3x^3 + 3x^2 - 2x + 9[/tex]

C. [tex]12x^8 - 15x^3 + 3x^2 - 2x + 9[/tex]

D. [tex]8x^8 + 4x^7 - 3x^3 + 3x^2 - 2x + 9[/tex]

Answer :

Sure! Let's add these two polynomials step-by-step:

1. Write down the given polynomials:

[tex]\[
\text{First polynomial: } 8x^8 - 9x^3 + 3x^2 + 9
\][/tex]

[tex]\[
\text{Second polynomial: } 4x^7 + 6x^3 - 2x
\][/tex]

2. Align and add the polynomials:

When adding polynomials, you add the coefficients of like terms. That means we need to combine terms that have the same powers of [tex]\(x\)[/tex].

- For [tex]\(x^8\)[/tex]: There is only one term, [tex]\(8x^8\)[/tex], from the first polynomial.
- For [tex]\(x^7\)[/tex]: There is only one term, [tex]\(4x^7\)[/tex], from the second polynomial.
- For [tex]\(x^3\)[/tex]: Combine [tex]\(-9x^3\)[/tex] from the first polynomial and [tex]\(6x^3\)[/tex] from the second polynomial. Add them: [tex]\(-9 + 6 = -3\)[/tex].
- For [tex]\(x^2\)[/tex]: There is only one term, [tex]\(3x^2\)[/tex], from the first polynomial.
- For [tex]\(x\)[/tex]: There is only one term, [tex]\(-2x\)[/tex], from the second polynomial.
- Constant term (no [tex]\(x\)[/tex]): There is only one term, [tex]\(9\)[/tex], from the first polynomial.

3. Write the combined polynomial:

[tex]\[
8x^8 + 4x^7 - 3x^3 + 3x^2 - 2x + 9
\][/tex]

So, the final answer is:

D. [tex]\(8x^8 + 4x^7 - 3x^3 + 3x^2 - 2x + 9\)[/tex]